1,147 Matching Annotations
  1. Last 7 days
    1. The command nix-shell will build the dependencies of the specified derivation, but not the derivation itself. It will then start an interactive shell in which all environment variables defined by the derivation path have been set to their corresponding values, and the script $stdenv/setup has been sourced. This is useful for reproducing the environment of a derivation for development.

      QUESTION: What exactly does nix-shell execute from the Nix expression (i.e., shell.nix, default.nix, etc.)?

      ANSWER: Based on my current understanding, the answer is everything. It calls $stdenv/setup (see annotation below) to set up the most basic environment variables (TODO: expand on this), and "injects" the most common tools (e.g., gcc, sed) into it.

      It also defines the phases (TODO: verify this) and builder functions, such as genericBuilder. For example, the default builder is just two lines:

      source $stdenv/setup

      TODO: pkgs/stdenv/generic/builder.sh is a mystery though.

      QUESTION: Once dropping into nix-shell, how do I know what phases to execute by looking at a default.nix? (E.g., [..]freeswitch/default.nix)

      ANSWER: As far as I can tell, one can override the phases in their Nix build expression (to build the derivation, see at the bottom), but they won't get executed as only the $stdenv/setup (see above) will get sourced, and no builders are called that, in return, invoke the phases (again, see above).

      So if one is using nix-shell

      • to create/hack on a package, the person has to manually invoke the builder or phases (TODO: still fuzzy on this subject)

      • to set up an environment, then one doesn't even have to worry about builders/phases because we just use nix-shell to clear the environment and to inject tools that we need for a given task

      QUESTION: When dropping into nix-shell, is this Nix expression (i.e., freeswitch/default.nix) executed? Or just parts of it?

      ANSWER: As stated above, all of the input Nix expression is evaluated, but no builders and build phases are called; although, nothing prevents one to override the phases, in case they are creating/hacking on a package.


      The command nix-shell will build the dependencies of the specified derivation, but not the derivation itself.

      What is the "derivation" here exactly? I know that it is a build expression, but does that mean the default.nix (or other Nix expression) nix-shell is invoked with?

      <sup>This statement also seems like a contradiction with how `nix-shell` works (i.e., if one issues `nix-shell -p curl`, then `curl` will be available in that sub-shell), but `-p` acts like a shortcut to as if `curl` had been listed in `buildInputs` so this is not the case.</sup>

      ANSWER: I have the feeling my confusion comes from the fact that the term "derivation" is used ambiguously in the manuals, sometimes to mean multiple things (see list below).

      TODO: Substantiate this claim, and make sure that it not coming from my misunderstanding certain topics.

      • Nix build expression (such as default.nix) whose output is going to become the store derivation itself (see last item at the bottom about the Nix manual's glossary definition)

      • store derivation.

      Had multiple cracks at unambiguously define what a derivation is, and here's a list of these:

      QUESTION: What is the difference between nix-shell -p and nix-shell invoked with a Nix expression of mkShell (or other that achieves the similar effect)?

      QUESTION: nix-shell does not create a sub-shell, so what does it do? (clarification: so nix-shell indeed does it; I confused it with nix shell)

  2. Apr 2021
    1. discrete probability distributions as there are a finite number of possible outcomes

      [[discrete probability distribution]] in contrast to [[continuous distribution]] by the number of outcomes : [[discrete probability distribution]] only have finite number of possible outcomes??????

    1. To eat lying down, while others served you, was a sign of power and luxury enjoyed by the elite. People further down the social ladder copied the laid-back dining style, if they could afford to.

      If this was a sign of luxury and power, eating lying down is very uncomfortable, so if it was uncomfortable, why would it still be a luxury?

    1. If no file is detected (in case, it's being run as part of a script or the command is being piped)

      How does it detect that it's being run non-interactively as part of a script?

      Is that distinct/different from detecting whether the command is being piped?

    1. can be easily invoked directly from shell prompt or script

      Can't expect / unbuffer / etc. (whatever this is attempting to contrast itself with) be easily invoked directly from shell prompt or script too??

      Okay, I guess you have to know more about how expect is invoked to understand what they mean. One glance at the examples, comparing them, and all becomes clear:

      empty -f -i in -o out telnet foo.bar.com
      empty -w -i out -o in "ogin:" "luser\n"

      I didn't realize that expect required/expected (no pun intended) to be used in scripts with its own shebang line:

      spawn telnet foo.bar.com 
      expect ogin {send luser\r}

      That does make it less easy/normal to use expect within a shell script.

      I was coming to the expect project from/for the unbuffer command, which by contrast, is quite easy to include/use in a shell script -- almost the same as empty, in fact. (Seems like almost a mismatch to have unbuffer command in expect toolkit then. Or is expect command the only odd one out in that toolkit?)

    1. Is there an OS agnostic way of doing this? I like the script command on macOS because you don't have to wrap the command in quotes. The script runs and sends output to the tty which is duplicated in the supplied file, but I can't seem to get the linux version to behave the same way... I'm probably doing something wrong. So what's the equivalent linux script command for this on macOS: script -q -t 0 tmp.out perl -e 'print "Test\n"' Test cat tmp.out Test
    1. I just don't understand why a finished episodically released game is still offered episodic.
    1. https://boardgamegeek.com/boardgame/183284/factory-funner/versions

      And now there are two versions with the nickname "Second edition": 2018 https://boardgamegeek.com/boardgameversion/404596/second-edition 2021 https://boardgamegeek.com/boardgameversion/556765/second-edition

      and a 3rd edition published prior to the current/new 2nd edition: 2019 https://boardgamegeek.com/boardgameversion/486693/third-edition

      Confusing all around.

      But I think the bottom line is that the 2021 version is in fact the same game and the newest rules tweaks:

      1. Added a sixth player
      2. Official variant to play without the quick grab element.
    1. I didn't get exactly how pty came into picture and what is the usage of that. Looking forward to get more info on that.
    2. How is related /dev/ack with /dev/tty?
    1. This question does not show any research effort; it is unclear or not useful Bookmark this question. Show activity on this post. I'm trying to filter the output of the mpv media player, removing a particular line, but when I do so I am unable to control mpv with the keyboard. Here is the command: mpv FILE | grep -v 'Error while decoding frame' When I run the command, everything displays correctly, but I am unable to use the LEFT and RIGHT keys to scan through the file, or do anything else with the keyboard. How do I filter the output of the program while retaining control of it?
    1. COPYRIGHT Rsync was originally written by Andrew Tridgell and is currently maintained by Wayne Davison. It has been improved by many developers from around the world. Rsync may be used, modified and redistributed only under the terms of the GNU General Public License, found in the file COPYING in this distribution, or at the Free Software Foundation.

      Only answered:

      • who maintains
      • what the license is
    1. All of these different ways of avoiding giving—hiding, turning goods into commodities, presenting oneself as an animator, lying—are manipulations of signs. Through these manipulations, one can conceal the link between people and material goods that marks possession and a responsibility to give

      Berman is using the specialized theories of linguistic anthropology to analyze life in Jajikon. How do these theories take us deeper into the worldview of her hosts? Or perhaps do we not need all this scientific mumbojumbo to understand how people avoid giving?

    2. speaking directly is dangerous: it can mean laying claim to a lie, a request, a re-fusal, a criticism, gossip, or knowledge. It can also mean taking responsibility for goods and marking oneself as a possessor who has an obligation to give. In such difficult situations, adults often use indirection to separate themselves from dan-gerous words and acts

      Are there other Pacific peoples who use indirect speaking because they believe direct speech is dangerous? Can you think of examples of indirect speech here in Hawai‘i or other Pacific places which connect them with Micronesia?

    3. Karlin leaned toward me with anticipation. ‘There is soda in Liklob.’

      These two sentences begin a story that will span the entire chapter. Using what you know about the rhetoric of ethnography, please tell me how Berman uses immediate and distanced narratives, as well as confessional and realistic styles, in order to tell her story across this whole chapter?

    4. f actions lead to power as opposed to the other way around, and age is power, then age is something not simply assigned by nature or the passing of time but, instead, achieved through action. I

      Goodness. Can someone explain what this passage means to me? It seems to be central to her argument in this book, but lines like "If actions lead to power as opposed to the other way around" seem very difficult to understand. What does this sentence means? Can you explain it, or do you need help understanding it? I guess this is a request for a comprehension check.

    5. Figure 1.5

      Dvorak taught us to think carefully about images. What is up with Berman's decision to pixelate out people's faces? What did you think of that?

    6. ust as marriage can be bittersweet, involving both loss and gain, sharing children in the RMI reinforces family ties while also creating feelings of sadness. ‘It was hard,’ Pinla said, referring to her effort to keep her daughter. ‘I am staying in their house.’Pinla soon returned to Jajikon. The baby stayed in Majuro, with Terij.

      I am curious to know what people think about this case of adoption. Berman seems to show a situation. We tend to be pro-Pacific Island culture and pro-human rights, but in this case, it seems a woman's right to raise her child is in tension with a cultural system where the elderly have power and the young must submit. What were your reactions to this passage? Am I mischaracterizing it?

    1. Which HTML tag I should use to enclose such notes to add a semantic meaning of a note that may be useful to read at a given point of a tutorial, but is not part of the main tutorial flow?
    2. I respectfully disagree with your assessment. You are referencing the quote "It's not appropriate to use the aside element just for parentheticals, since those are part of the main flow of the document." However the OP specifically said that they are looking for a semantic element for "a note that may be useful to read at a given point of a tutorial, but is not part of the main tutorial flow". That is what "aside" is for. It's not part of the main content flow.

      That's a tough one. I can see it both ways.

    1. Tangentially is defined as briefly mentioning a subject but not going into it in detail, or is defined as going off in a different direction.

      in the case of

      briefly mentioning a subject but not going into it in detail the topic/subject need not be related at all (it sounds like).

      What about in the case fo:

      is defined as going off in a different direction. Does the fact that it's going off in a different direction imply that it at least starts out connected/related to the original (starting point) subject (as it does in the geometry sense of tangential)? Or does it permit "jumping" to another topic (in another direction) without being related/connected at all??

      I don't think I like this definition very much. It doesn't quite fit the sense I'm trying to use it for in my tag:

      tangentially related content (aside)

      Ah, here's a definition that matches what I thought it meant (one of the senses anyway): https://hyp.is/3Bn2bpZ7Eeu3Ok8vg03AVA/www.merriam-webster.com/dictionary/tangential

  3. Mar 2021
    1. Samaria has spread beyond Tanna as village families developed new trans-island connections

      We know from Hau‘ofa that islanders are mobile. But given the fact that Monty includes Maui and a Scottish missionary are feature characters in the book, and also given the fact that he now includes in his ethnography the Tannaese diaspore in Port Vila, what is the topic of Monty's book? Tanna? Samaria? Islanders? Something else?

    2. It is a tricky business when one’s culture goes on sale in the global tourism marketplace as primitive and peculiar.

      Monty seems to believe that tourism is a pretty good deal for Tanna. Given what we know about tourism in Hawai‘i (and perhaps other places you'd like to share about), do you agree or disagree with him? And why?

    3. Anthropologists, too, like to tell other people’s stories. We carry these from one place to another. And we, too, hope that this cultivates new understandings and deeper mutual appreciation among those living on last, or rst, islands

      Monty seems to be making an argument here that anthropologists and islanders are very similar. What is his argument here and do you agree with it?

    1. Nevertheless, co-hyponyms are not necessarily incompatible in all senses. A queen and mother are both hyponyms of woman but there is nothing preventing the queen from being a mother.

      not necessarily incompatible in all senses.

      so is this only a concern/possibility when the word in question is a polyseme?

      but there is nothing preventing the queen from being a mother

      The meaning of the "incompatibility" relation seems really ambiguous. What does that mean precisely?

      And how would we know for sure if an incompatibility (such as a peach is not a plum) or lack of incompatibility (a queen can be a mother and a mother can be a queen) is a sufficient condition to cause it to be or not be a co-hyponym?

      Oh. I guess it says

      Co-hyponyms are often but not always related to one another by the relation of incompatibility.

      so it actually can't ever be used to prove or disprove (sufficient/necessary condition) that something is a co-hyponym. So that observation, while interesting, is not helpful in a practical / deterministic way...

    2. It consists of two relations; the first one being exemplified in "An X is a Y" (simple hyponymy) while the second relation is "An X is a kind/type of Y". The second relation is said to be more discriminating and can be classified more specifically under the concept of taxonomy.

      So I think what this saying, rather indirectly (from the other direction), if I'm understanding correctly, is that the relationships that can be inferred from looking at a taxonomy are ambiguous, because a taxonomy includes 2 kinds of relationships, but encodes them in the same way (conflates them together as if they were both hyponyms--er, well, this is saying that the are both kinds of hyponyms):

      • "An X is a Y" (simple hyponymy)
      • "An X is a kind/type of Y".

      Actually, I may have read it wrong / misunderstood it... While it's not ruling out that simple hyponymy may sometimes be used in a taxonomy, it is be saying that the "second relation" is "more specifically under the concept of taxonomy" ... which is not really clear, but seems to mean that it is more appropriate / better for use as a criterion in a taxonomy.

      Okay, so define "simple hyponymy" and name the other kind of hyponymy that is referenced here.

    1. The Taylor series of a real or complex-valued function f (x) that is infinitely differentiable at a real or complex number a is the power series f ( a ) + f ′ ( a ) 1 ! ( x − a ) + f ″ ( a ) 2 ! ( x − a ) 2 + f ‴ ( a ) 3 ! ( x − a ) 3 + ⋯ , {\displaystyle f(a)+{\frac {f'(a)}{1!}}(x-a)+{\frac {f''(a)}{2!}}(x-a)^{2}+{\frac {f'''(a)}{3!}}(x-a)^{3}+\cdots ,}

      What's the connection between a series and the function?

      -- because of the phrase: "the Taylor series of a ... function "

    1. semantic domain or semantic field

      What, then, is the difference between a semantic domain and a semantic field? The way they are used here, it's almost as if they are listing them in order to emphasis that they are synonyms ... but I'm not sure.

      From the later examples of basketball (https://hyp.is/ynKbXI1BEeuEheME3sLYrQ/en.wikipedia.org/wiki/Semantic_domain) and coffee shop, however, I am pretty certain that semantic domain is quite different from (broader than) semantic field.

    1. (Not answered on this stub article)

      What, precisely, is the distinction/difference between a semantic class and a semantic field? At the very least, you would say that they are themselves both very much within the same semantic field.

      So, is a semantic class distinct from a semantic field in that semantic class is a more well-defined/clear-cut semantic field? And a semantic field is a more fluid, nebulous, not well-defined field (in the same sense as a magnetic field, which has no distinct boundary whatsoever, only a decay as you move further away from its source) ("semantic fields are constantly flowing into each other")?

      If so, could you even say that a semantic class is a kind of (hyponym) of semantic field?

      Maybe I should pose this question on a semantics forum.

    1. those aspects of a linguistic unit, such as a morpheme, word, or sentence,

      Speaking of ambiguity...

      Are the examples in the list "such as a morpheme, word, or sentence" examples of

      • aspects of a linguistic unit or of:
      • linguistic units themselves ?

      Unless you are already fairly familiar with those terms -- in particular, linguistic unit -- it may not be clear.

      I believe these are given as examples of "linguistic unit", in order to clarify what we mean by "linguistic unit" — perhaps (ironically) precisely because many people would be unfamiliar with that expression/term.

    1. Function (computer science) Function (engineering) Function (mathematics)

      Is this a polyseme?

      Or is that only the case if the different distinct senses are all within the same "field"?

    1. There is little consideration of what is lost by not selecting locally. Apart from losing high-quality people who are unwilling to leave their communities, we see three losses: (a) a sense of social responsibility and depth of commitment to parts of the local community; (b) a sense of respect for and understanding of the community's resources and cultural assets that could be tapped into (see Gonzalez, Moll, & Amanti, 2005, on "funds of knowledge"); and (c) a connection to the community that facilitates working with it

      Does UMaine hire its own graduates? Or do they consider this inbreeding?

    1. How to install VIM with all options/features? - VIM
    2. I have VIM on Mac & CentOS. So, I see people are writing about -xterm_clipboard, -lua, ... Is there an simple way to install it all? or we have to enable options one-by-one and compile/recompile it?

      I had similar question... how to get --servername support.

  4. kubernetes.io kubernetes.io
    1. even if it is being drained of workload applications.

      Q: 那岂不是会出问题? 有什么事件会被触发吗?

    2. Pods that are part of a DaemonSet tolerate being run on an unschedulable Node.

      Q: 标记node为不可调度本来就不会驱逐正在运行的node吧 A: daemonset中的pod是可以在后面动态添加的

    3. Path to credentials to authenticate itself to the API server.

      那为为什么叫 kubeconfig?而不是kube-credentials-path? 参见 https://github.com/zecke/Kubernetes/blob/master/docs/user-guide/kubeconfig-file.md kubeconfig 就是存鉴权信息地方

    4. Kubernetes keeps the object for the invalid Node and continues checking to see whether it becomes healthy.You, or a controller, must explicitly delete the Node object to stop that health checking.


    1. Or even a simple 1-liner in the Contract that references an AR Model so you don't have to rewrite the validations again in that contract, or have to choose between writing the validations once either in the contract there or in the AR Model?
    1. Durham

      does this trajectory say something: Winston-Salem-Durham-hill above Harlem.... is this person a long way from home?

    1. Essentially we're trying to figure out when it's appropriate for "my" code to become "everyones" code, and if there are steps in between. ("Standard library", for example.)
    1. Self answer: 4d00bdf it seems to be to prevent shifting lines in source maps.
    2. This semi-colon is added to prevent changing the code behaviour (the famous line ending with parentheses, etc) Most people will use a JS minifier If they don't, a single extra character is unlikely to change much If I'm right about all the above: Why don't we simply always add a semi-colon regardless of what the file ends with?
    1. What is the point of avoiding the semicolon in concat_javascript_sources

      For how detailed and insightful his analysis was -- which didn't elaborate or even touch on his not understanding the reason for adding the semicolon -- it sure appeared like he knew what it was for. Otherwise, the whole issue would/should have been about how he didn't understand that, not on how to keep adding the semicolon but do so in a faster way!

      Then again, this comment from 3 months afterwards, indicates he may not think they are even necessary: https://github.com/rails/sprockets/issues/388#issuecomment-252417741

      Anyway, just in case he really didn't know, the comment shortly below partly answers the question:

      Since the common problem with concatenating JavaScript files is the lack of semicolons, automatically adding one (that, like Sam said, will then be removed by the minifier if it's unnecessary) seems on the surface to be a perfectly fine speed optimization.

      This also alludes to the problem: https://github.com/rails/sprockets/issues/388#issuecomment-257312994

      But the explicit answer/explanation to this question still remains unspoken: because if you don't add them between concatenated files -- as I discovered just to day -- you will run into this error:

         (intermediate value)(...) is not a function
             at something.source.js:1

      , apparently because when it concatenated those 2 files together, it tried to evaluate it as:

           // other.js
         (function() {
           // something.js

      It makes sense that a ; is needed.

    1. Yes, but honestly, and no offense intended, but I don't see the harm in these type questions, nor why some people are offended when they are asked. If I owed a website, I wouldn't mind it because it just creates more pages that can be indexed. I see it as helping the website. But, I did look and didn't see a simple answer. Again, no offense is intended. I've just never understood the complaints.
    1. Thinking can be identified in many different sorts of inscriptions: written words, sounds, images, traces.

      La pensée n'est donc que traces. Dirais-tu que la voix, sans technologie d'enregistrement, n'est que pensée dans la mesure où elle a une « conscience » pour la recevoir, c'est-à-dire une surface sur laquelle s'inscrire?

      On pourrait même stipuler que la pensée n'est autre qu'énergie transformée et emmagasinée. Mes cordes vocales produisent des ondes sonores (une forme d'énergie) qui sont ensuite reçues par un système auditif qui l'interprète et envoie des signaux électromagnétique (toujours de l'énergie) au cerveau.

    1. thought always corresponds to the material conditions of its production

      matérialisme dialectique?

    2. Dogmatic realism

      Serait-il plus clair de parler de réalisme direct, « naïf »?

    3. In today’s digital environment, this question arises in a particular way, and this text could not exist independently of the technological environment in which it emerges.

      Il faudrait définir précisément ce que "technological environment" signifie, et pourquoi pas plutôt "technical environment" par exemple (sans vouloir couper les cheveux en 4) ?

    4. This is the paradox of access.

      Ce "paradoxe de l'accès" pourrait aussi être comparé avec la question de l'accès aux données numériques ? Les données sont produites, stockées, mais sont-elles encore accessibles, compréhensibles (par des machines ou des humains) ou exploitables ?

    1. the concept of world will be tentatively defined as follows: the world is everything which is.

      Comment cette définition minimale interagit-elle avec la définition de monde en logique modale comme ensemble logique (non-contradictoire) de propositions nécessaires et contingentes (Leibniz)? Pour ses fins méthodologiques, les logiciens contemporains (XXe) semblent fonder une ontologie non sur les objets, mais des propositions appréhendables par le langage. Il semble, aux premiers abords, que la logique modale reformule un certain idéalisme. Mais la position des logiciens est-elle réellement irréconciliable avec celle du new materialism?

    1. ab­sorbed

      jazz and 'city vs rustic' as hot and cold? don't follow rly

    2. It is this implosive factor that alters the position of the Negro, the teen-ager, and some other groups. They can no longer be contained, in the political sense of limited association. They are now involved in our lives, as we in theirs, thanks to the electric media.

      they can no longer be CONTAINED? is he saying they can no longer be blissfully ignored like above?

    3. The Theater of the Absurd

      what are these theaters he's talking about??



  5. Feb 2021
    1. To whom did you sell your keys and at what kind of rates? https://steamcommunity.com/id/playa131 for example resells them and might be the source for DIG's purchases.
    1. Currently, only Right signals are wired up.

      So what happens if a task returns a Left signal?? Will it still go Right? Will it error?

    1. For each output declared in outputs, the corresponding environment variable is set to point to the intended path in the Nix store for that output. Each output path is a concatenation of the cryptographic hash of all build inputs, the name attribute and the output name. (The output name is omitted if it’s out.)

      QUESTION: So when I see $out in a builder script, it refers to the default output path because the output attribute in the Nix expression has never been explicitly set, right?

    2. derivationA description of a build action. The result of a derivation is a store object. Derivations are typically specified in Nix expressions using the derivation primitive. These are translated into low-level store derivations (implicitly by nix-env and nix-build, or explicitly by nix-instantiate).

      Organically related to the annotation regarding my nix-shell confusion.

      The dissection of this definition to show why I find it lacking:

      A description of a build action.

      The first (couple) time(s) I read the manuals, this description popped up in many places, and I identified it with Nix expression every time, thinking that a derivation is a synonym for Nix expression.

      Maybe it is, because it clearly tries to disambiguate between store derivations and derivation in the last sentence.

      The result of a derivation is a store object.

      Is this store object the same as a store derivation?

      Derivations are typically specified in Nix expressions using the `derivation primitive. These are translated into low-level store derivations (implicitly by nix-env and nix-build, or explicitly by nix-instantiate).

      QUESTION: So, the part of the Nix build expression (such as default.nix) where the derivation primitive is called (explicitly or implicitly, as in mkDerivation) is the derivation, that will be ultimately be translated into store derivations?

      ANSWER: Start at section 15.4 Derivation.

      QUESTION: Also, why is typically used here? Can one define derivations outside of Nix expressions?

      ANSWER(?): One could I guess, because store derivations are ATerms (see annotation at the top), and the Nix expression language is just a tool to translate parameterized build actions into concrete terms to build a software package. The store derivations could be achieved using different means; e.g., the way Guix uses Guile scheme to get the same result))

      I believe, that originally, derivation was simply a synonym to store derivation. Maybe it still is, and I'm just having difficulties with reading comprehension but I think the following would be less misleading (to me and apart from re-writing the very first sentence):

      Derivations are typically the result of Nix expressions calling the derivation primitive explicitly, or implicitly usingmkDerivation`. These are translated into low-level store derivations (implicitly by nix-env and nix-build, or explicitly by nix-instantiate).

    3. $stdenv/setup

      QUESTION: Does this refer to pkgs/stdenv/generic/setup.sh? According to 6.5 Phases in the Nixpkgs manual?

      ANSWER: I'm pretty sure it does. It sets up the environment (not sure how yet; I see the env vars, but not the basic commands - sed, awk, etc. - that are listed below) and defines a bunch of functions (such as genericBuilder) but it doesn't call these functions!

    4. substitute

      this is another key topic. Also:

      • substitute vs. substituter => this (I think)

      See annotations with the substitute tag

    5. When you ask Nix to install a package, it will first try to get it in pre-compiled form from a binary cache. By default, Nix will use the binary cache https://cache.nixos.org; it contains binaries for most packages in Nixpkgs. Only if no binary is available in the binary cache, Nix will build the package from source. So if nix-env -i subversion results in Nix building stuff from source, then either the package is not built for your platform by the Nixpkgs build servers, or your version of Nixpkgs is too old or too new.

      binary caches tie in with substitutes somehow; get to the bottom of it. See annotations with the substitute tag.

      Maybe this?

    6. At the same time, it is not possible for one user to inject a Trojan horse into a package that might be used by another user.
    7. Chapter 6. SecurityNix has two basic security models. First, it can be used in “single-user mode”, which is similar to what most other package management tools do: there is a single user (typically root) who performs all package management operations. All other users can then use the installed packages, but they cannot perform package management operations themselves.Alternatively, you can configure Nix in “multi-user mode”. In this model, all users can perform package management operations — for instance, every user can install software without requiring root privileges. Nix ensures that this is secure. For instance, it’s not possible for one user to overwrite a package used by another user with a Trojan horse.

      Would have been nice to link these to the install chapter where single- and multi-user modes were mentioned.

      How would this look in a topic-based documentation? I would think that his chapter would be listed in the pre-requisites, and it could be used to buld different reading paths (or assemblies in DocBook, I believe) such as practical, depth-first (if there are people like me who want to understand everything first), etc.

    8. reentrancy
    9. nix-shell '<nixpkgs>' -A pan

      What is happening here exactly?

      nix-shell's syntax synopsis always bugged because it looks like this

      nix-shell [--arg name value] [--argstr name value] [{--attr | -A} attrPath] [--command cmd] [--run cmd] [--exclude regexp] [--pure] [--keep name] {{--packages | -p} packages...  | [path]}

      and the canonical example is nix-shell '<nixpkgs>' -A pan; what tripped me up is that path is usually the first in examples, and I thought that the position of arguments are strict. As it turns out, nix-shell -A pan '<nixpkgs> is just as valid.

      Side note<br> Apparently there is no standard for man pages. See 1, 2.

      '<nixpkgs>' path is the one specified in the NIX_PATH environment variable, and -A pan looks up the pan attribute in pkgs/top-level/all-packages.nix in the Nixpkgs repo.

    1. 17.3. Fixed point

      QUESTION: What is a fixed-point of a function?

      ANSWER: See this video) at least, and the Fixed-point (mathematics)) wikipedia article:

      In mathematics, a fixed point (sometimes shortened to fixpoint, also known as an invariant point) of a function is an element of the function's domain that is mapped to itself by the function. That is to say, c is a fixed point of the function f if f(c) = c. This means

      f(f(...f(c)...)) = f n(c) = c

      an important terminating consideration when recursively computing f. A set of fixed points is sometimes called a fixed set.

      For example, if f is defined on the real numbers by f(x)=x^{2}-3x+4,}, then 2 is a fixed point of f, because f(2) = 2.

      There is also the wiki article fixed-point combinator that actually plays a role here, but read through the articles in this order.

      Then dissect the Stackoverflow thread What is a Y combinator?, and pay attention to the comments! For example:

      According to Mike Vanier's description, your definition for Y is actually not a combinator because it's recursive. Under "Eliminating (most) explicit recursion (lazy version)" he has the lazy scheme equivalent of your C# code but explains in point 2: "It is not a combinator, because the Y in the body of the definition is a free variable which is only bound once the definition is complete..." I think the cool thing about Y-combinators is that they produce recursion by evaluating the fixed-point of a function. In this way, they don't need explicit recursion. – GrantJ Jul 18 '11 at 0:02


      Other resources in no particular order:

      QUESTION: How the hell did they come up with the idea of using this with Nix and package management? (..and who? I remember a video saved somewhere, but maybe that was about overlays)

      QUESTION: ... and how does it work in this context?

      ANSWER: Well, not an answer yet, but this may be something in the right direction:


    2. there's no ldconfig cache either. So where does bash find libc?

      QUESTION: What is ldconfig cache?

      QUESTION: What is libc and why does Bash need it?

    3. Derivations/packages are stored in the Nix store as follows: /nix/store/hash-name, where the hash uniquely identifies the derivation (this isn't quite true, it's a little more complex), and the name is the name of the derivation.

      QUESTION: So the Nix store houses derivations and not the built packages?

      QUESTION: Are the hashes in the Nix store not unique?

    1. The latter are important examples which usually also exist in "purely" functional programming languages.

      How can they exist and it still be considered pure??

      I guess that's not quite the same / as bad as saying something had side effects in a purely functional programming context, right?

    1. provide interfaces so you don’t have to think about them

      Question to myself: Is not having to think about it actually a good goal to have? Is it at odds with making intentional/well-considered decisions?  Obviously there are still many of interesting decisions to make even when using a framework that provides conventions and standardization and makes some decisions for you...

    1. What is the opposite of free content?

      The opposite of free/open-source software is proprietary software or non-free software (https://en.wikipedia.org/wiki/Proprietary_software).

      So should we call the opposite of free content "non-free content"? Or "proprietary content"?

      Seems likes either would be fine.

      Looks like https://en.wikipedia.org/wiki/Wikipedia:Non-free_content prefers the term "non-free content".

      Couldn't find anyone contrasting these 2 terms (like I could no doubt find for software):

      Not to be confused with:

      • paid content ... just like:
      • free content should not be confused with gratis content (?)
      • free software should not be confused with freeware
    1. Why then sending the SIGINT manually to the shell doesn't kill the child, e.g. 'kill -2 <shell-pid>' doesn't do anything to a child process while Ctrl-C kills it?
    1. Specifying a name and a src is the absolute minimum Nix requires.

      Didn't they mean what mkDerivation requires?

      I have been jumping around in this manual, so not sure about what arguments does derivation require.

    1. What do you get when you add a sudden surge of demand to an equally sudden loss of capacity? A crisis, whose roots lie in a decade’s worth of deregulation and cost-cutting, of an energy “independence” that has left the state at the mercy of the elements.

      The author is asking a rhetorical question and answering it immediately. He is doing this not only to clear one of the audience's questions regarding the consequences of Texas situations, but also to make the government officials more guilty for leaving Texas in this situation.

    1. compose(Add, x: x, y: 3)

      How is this better than simply:

      Add.run(x: x, y: 3)


      I guess if we did that we would also have to remember to handle merging errors from that outcome into self...

    1. However, using channels is not fully reproducible, as a channel may evolve to incorporate updates.

      TODO: Find other sources about this topic. I remember this mentioned already (and it makes) sense, but need to learn more.

      TODO: What is a better alternative? An own repo? Flakes? Can cachix help?

      It says right below that pinning can help but keep looking.

      When package reproducibility become a major concern, as it is the case in this tutorial, it is preferable to refer to a pinned version of the nixpkgs repository instead — i.e, a specific commit of the repository or an immutable archived tarball. The ability to pin the version of nixpkgs is powerful, it will ensure that a package is always constructed from the same Nix source. As we go deeper in the tutorial we avoid using channels in favor of pinned environments.

    1. Service Balance = Value of service exports –Value of service Imports

      Question: How do they measure the value of import services?



    1. An asthmatic, she had been taken to the hospital nearly 30 times in less than three years and suffered numerous seizures

      Does this relate and increase how it impacts the pollution aspect compared to if it had been someone without asthma?

    2. he first person in Britain to officially have air pollution listed as a cause of death,

      How would this relate and compare to other countries in general? Or in more specific areas in places that have higher amounts of people dying from pollution?

    1. you'll want to update Devise's generated views to remove references to passwords, since you don't need them any more

      Doesn't this contradict the statement

      This strategy plays well with most other Devise strategies

      (which includes password strategies)?

      One thing that wasn't clear from their instructions was whether magic links could be used as an option in addition to regular password log-ins. On the one hand they say:

      This strategy plays well with most other Devise strategies (see notes on other Devise strategies).

      but on the other hand they say:

      you'll want to update Devise's generated views to remove references to passwords, since you don't need them any more

    1. While all these things were happening in various places, Saturnian Juno sent Iris from heaven to brave Turnus,

      We continually see Juno try to intervene, all the while working in accordance with the will of Jupiter and the fates. This begs the question, are gods bound by the fates, or do they shape them? Juno is queen of heaven, a leader of the gods, so why cant she shape fate as Jupiter seems to be able to?

    1. unfamiliar—that is, a metaphorical Journey in which designers move into unchartered territory by attempting to formulate what hasn’t yet been formulated.

      Head Scratcher: using this simple explanation of "unfamiliar" we can see that it is difficult to navigate through territory that has not been properly formed yet or mapped out.

      How do we move forward as Instuctional Designers into the future of Education and Instruction?

      My best efforts so far have been to never be afraid to try new models or technology to lead your instruction.

    1. but what does it mean to be clever, and how can you teach someone to be clever?

      Head Scratcher: How do you teach "cleverness"? This is a tough question and I feel that it is hard to understand for most instructors. How do I get my students to be more creative and clever, I believe we usually feel that students either are or are not creative and thats the end of the story. So really maybe we are the ones at fault for not teaching studetns to be "creative".

    1. We still must decide how to present certain information, but it doesn’t have to be at the cost of another medium.

      Headscratcher: How do we make sure, in our times creating instuction, that we do not neglect a medium that could be used for instruction?

      I feel that one way could be to allow learners choice in how they respond to prompts and learning. I feel that this could allow for students to use their gifting and talents to excel and produce amazing work.

    1. the most productive environment possible for people that use their computer to create.What is a productive environment?How do you measure productivity in an operating system environment?How do you compare YOUR distribution to other distributions when it comes to productivity?Is the way in which 'people that use their computer to create' (creators) the same across all professions and activities?Does a photographer have the same requirements for a productive environment as a software engineer?Why do you think your distribution will be the best for delivering a productive environment than any other Linux distribution?
    1. deconstructing Brazilian gender roles through their performances

      An interesting concept I'd like to consider and interrogate. Does exacerbating and essentially parodying gender roles ACTUALLY work to dismantle those roles, or does it enforce them?

      No strong opinion yet. Come back to this.

    1. A blue-grey spider lay on her exposed cheek. But when I held the match closer there was nothing there, nothing but the faint outlines of a dimple.

      Could there be any other reason or meaning behind the confusing of a pimple with a blue-grey spider, except for the narrator being drunk?

  6. Jan 2021
    1. A value of -1 will disable the limit and the chunk size will grow indefinitely.

      Below it mentions a value of off, where does -1 come from? And since --vfs-read-chunk-size has a nonzero default value does that mean that this feature is on by default, and with an unlimited limit?