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author | Bryan Newbold <bnewbold@archive.org> | 2019-05-18 16:23:07 -0700 |
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committer | Bryan Newbold <bnewbold@archive.org> | 2019-05-18 16:23:07 -0700 |
commit | 97a3a8ea4122ed97d29176c570389e1db6a91b44 (patch) | |
tree | 5010e85e067d3ad3d2502353e57de02785c26dfd /posts/elm-everything-broken.md | |
parent | 1dd4b642da5dfb9fed999b4ca938aba460243e78 (diff) | |
download | bnewnet-97a3a8ea4122ed97d29176c570389e1db6a91b44.tar.gz bnewnet-97a3a8ea4122ed97d29176c570389e1db6a91b44.zip |
move finished posts into sub-directories
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diff --git a/posts/elm-everything-broken.md b/posts/elm-everything-broken.md deleted file mode 100644 index a9978d1..0000000 --- a/posts/elm-everything-broken.md +++ /dev/null @@ -1,427 +0,0 @@ -Title: Everything Is Broken (Installing Elm Edition) -Author: bnewbold -Date: 2016-05-06 - -*This post is a narrative rant (in the same vein of Dan Luu's ["Everything is -Broken"][danluu] post) about my problems one afternoon getting a Fancy New -Programming Language to work on my laptop. [Skip down](#nowwhat) for my -thoughts on solutions.* - -[danluu]: https://danluu.com/everything-is-broken/ - -<br /> - -<div class="sidebar"> -<a href="https://www.youtube.com/watch?v=oYk8CKH7OhE"> -<img src="/static/fig/elm-evan-talk.jpg" alt="photo of E.C. giving an elm talk" width="240px" /> -</a> -</div> - -A few folks here at the [Recurse Center][rc] had nice things to say about the -[Elm programming language][rc], and after watching Evan Czaplicki's ["Let's Be -Mainstream" talk][0] I got pretty excited also. "Let's try Elm!" and the -adventure begins. - -[rc]: https://recurse.com/ -[elm]: https://elm-lang.org -[0]: https://www.youtube.com/watch?v=oYk8CKH7OhE - -First I go in the front door with the [install page][install], which redirects -me to a page which instructs me to use npm. - -[install]: http://elm-lang.org/install - -Hrm, I've had painful experiences with npm in the past, and anyways, isn't -the Elm compiler implemented in Haskell? Why are they using a package -management tool for Javascript libraries for installation? No thanks, I'll -[build from source][build], following these directions from the `README.md`: - -[build]: https://github.com/elm-lang/elm-platform - - # If you are on LINUX, you need to install a dependency of elm-repl. - # Uncomment the following line and run it. - # sudo apt-get install libtinfo-dev - - # if you are on windows, or some other place without curl, just download this file manually - curl https://raw.githubusercontent.com/elm-lang/elm-platform/master/installers/BuildFromSource.hs > BuildFromSource.hs - - runhaskell BuildFromSource.hs 0.16 - -<!-- If you don't know how to clone a repo, are you really going to know how to -get `cabal` set up, open a terminal and paste a command, etc? --> - -Weird that these build-from-source directions involve curl-to-file magics. Why -not just clone the repo and use a Makefile, which is roughly the same number of -commands to enter? I clone repo and run the build script from there instead. -I'm on Debian stable ("jessie"), so installing GHC (the most popular way to use -Haskell) is easy. I seem to have a recent-ish version of cabal: - -<pre class="terminal"> -bnewbold@eschaton$ cabal --version -cabal-install version 1.20.0.3 -using version 1.20.0.2 of the Cabal library -</pre> - -... so I think i'm ready to go ahead run the `BuildFromSource.hs` script: - -<pre class="terminal"> -bnewbold@eschaton$ runhaskell ~/src/elm-platform/installers/BuildFromSource.hs 0.16 - -GHCi runtime linker: fatal error: I found a duplicate definition for symbol -_hs_bytestring_long_long_uint_hex -whilst processing object file -/home/bnewbold/.cabal/lib/x86_64-linux-ghc-7.6.3/bytestring-0.10.6.0/HSbytestring-0.10.6.0.o -This could be caused by: -* Loading two different object files which export the same symbol -* Specifying the same object file twice on the GHCi command line -* An incorrect `package.conf' entry, causing some object to be - loaded twice. -GHCi cannot safely continue in this situation. Exiting now. Sorry. -</pre> - -Uh-oh! Not sure what that means. A search returns [a FAQ entry][faq-entry] -about "Duplicate Directions" which talks about linker flags, but *I* didn't -compile anything by hand so it doesn't seem like *I* have done anything wrong. -I'll try updating `cabal`'s package index: - -[faq-entry]: https://wiki.haskell.org/GHC/FAQ#Duplicate_Definitions - -<pre class="terminal"> -bnewbold@eschaton$ cabal update -Downloading the latest package list from hackage.haskell.org -cabal: Failed to download -http://hackage.haskell.org/packages/archive/00-index.tar.gz : ErrorMisc "Error -HTTP code: 502" -</pre> - -No go! At first I assumed I was doing something wrong, or maybe the WiFi was -flakey, but it turns out that the Hackage package repository [is -down](https://status.haskell.org/): - -> hackage.haskell.org down -> -> Full Service Disruption -> -> [Investigating] The hackage server is in an out of memory condition. We're investigating. - -<div class="sidebar"> -As far as I know, the only Debian packages out of the huge stable archive which -don't receive security updates are web browsers, mediawiki, and all V8/node.js -packages and libraries. -</div> - -Well, it wasn't even clear if updating my package index would fix the problem, -it was just a wild guess. I'll give up and try npm, which these days has been -[sort of packaged][deb-node] in Debian. I'll just uninstall npm when I'm done -installing Elm. I install with `apt` (which pulls in a huge list of `nodejs` -packages), but then can finally run: - -[deb-node]: https://www.debian.org/releases/stable/amd64/release-notes/ch-information.en.html#libv8 - -<pre class="terminal"> -bnewbold@eschaton$ npm install elm -| -> elm@0.16.0 install /home/bnewbold/bin/node_modules/elm -> node install.js - -sh: 1: node: not found -npm WARN This failure might be due to the use of legacy binary "node" -npm WARN For further explanations, please read -/usr/share/doc/nodejs/README.Debian - -npm ERR! elm@0.16.0 install: `node install.js` -npm ERR! Exit status 127 -npm ERR! -npm ERR! Failed at the elm@0.16.0 install script. -npm ERR! This is most likely a problem with the elm package, -npm ERR! not with npm itself. -npm ERR! Tell the author that this fails on your system: -npm ERR! node install.js -npm ERR! You can get their info via: -npm ERR! npm owner ls elm -npm ERR! There is likely additional logging output above. - -[...] -<!-- -npm ERR! System Linux 3.16.0-4-amd64 -npm ERR! command "/usr/bin/nodejs" "/usr/bin/npm" "install" "elm" -npm ERR! cwd /home/bnewbold/bin -npm ERR! node -v v0.10.29 -npm ERR! npm -v 1.4.21 -npm ERR! code ELIFECYCLE -npm ERR! -npm ERR! Additional logging details can be found in: -npm ERR! /home/bnewbold/bin/npm-debug.log -npm ERR! not ok code 0 ---> -</pre> - -<div class="sidebar"> -Later I learned that I could have instead installed the nodejs-legacy -package, which just installs a symlink /usr/bin/node which points to -/usr/bin/nodejs. -</div> - -Looks like Debian wants to refer to node.js as "`nodejs`" while npm/Elm expects -it to be "`node`". Ok, I create this shim named `node` in my `~/bin` directory -(which is on my `$PATH`), and make it executable: - -<pre class="terminal"> -#!/bin/sh -nodejs $* -</pre> - -Now I can do things like: - -<pre class="terminal"> -bnewbold@eschaton$ node --version -v0.10.29 -</pre> - -Great! Now let's install Elm with npm! - -<pre class="terminal"> -bnewbold@eschaton$ npm install elm - -> elm@0.16.0 install /home/bnewbold/bin/node_modules/elm -> node install.js - -Downloading Elm Reactor assets from https://dl.bintray.com/elmlang/elm-platform/0.16.0/elm-reactor-assets.tar.gz -Error communicating with URL https://dl.bintray.com/elmlang/elm-platform/0.16.0/linux-x64.tar.gz Error: CERT_UNTRUSTED -npm WARN This failure might be due to the use of legacy binary "node" -npm WARN For further explanations, please read -/usr/share/doc/nodejs/README.Debian - -npm ERR! elm@0.16.0 install: `node install.js` -npm ERR! Exit status 1 -npm ERR! -npm ERR! Failed at the elm@0.16.0 install script. -npm ERR! This is most likely a problem with the elm package, -npm ERR! not with npm itself. -npm ERR! Tell the author that this fails on your system: -npm ERR! node install.js -npm ERR! You can get their info via: -npm ERR! npm owner ls elm -npm ERR! There is likely additional logging output above. - -npm ERR! System Linux 3.16.0-4-amd64 -npm ERR! command "/usr/bin/nodejs" "/usr/bin/npm" "install" "elm" -npm ERR! cwd /home/bnewbold/bin -npm ERR! node -v v0.10.29 -npm ERR! npm -v 1.4.21 -npm ERR! code ELIFECYCLE -npm ERR! -npm ERR! Additional logging details can be found in: -npm ERR! /home/bnewbold/bin/npm-debug.log -npm ERR! not ok code 0 -</pre> - -Whoops. There is [a github issue][elm-issue] that has some tips about this: the -recommended solutions online are basically "upgrade node.js and npm" or -"disable SSL security". That doesn't sound great, but i'm feeling very -impatient at this point so I tried disabling SSL checks with `npm config set ca -null`, but even then I get the certificate error. Enough of that approach: - -[elm-issue]: https://github.com/elm-lang/elm-platform/issues/100 - -<pre class="terminal"> -sudo apt remove npm nodejs -rm ~/bin/node -</pre> - -Poking around a bit more, I find the promisingly-titled "`fubar.sh`" script in -the `elm-platform` repo cloned earlier, which seems to nuke the local user's -Haskell (`cabal`) stuff (but doesn't muck with system-wide package, eg `apt` -managed GHC libraries). After running `fubar.sh` the `BuildFromSource.hs` -script seems to start working (success!), but Hackage is still down (now, an -hour after I started this process, approaching 5 hours total downtime), so I -can't install dependencies. - -I search for a hackage mirror and find that [FPComplete runs -one](https://www.fpcomplete.com/blog/2015/03/hackage-mirror). In addition to -their configuration instructions I had to set `remote-repo-cache` in my -`~/.cabal/config`, like so: - - remote-repo: hackage.fpcomplete.com:http://hackage.fpcomplete.com/ - remote-repo-cache: /home/bnewbold/.cabal/packages-fpcomplete - -After that I `cabal update` and run the `BuildFromSource.hs` script again. It -fails to build the dependency `websockets-snap`, but I try installing that -regularly (`cabal install websockets-snap`) and that works, and then all the -dependencies with BuildFromSource.hs build. Yay! - -I still get an error with compiling Elm itself though: - - src/Elm/Package.hs:60:25: - Not in scope: `<$>' - Perhaps you meant `</>' (imported from System.FilePath) - -It [sounds like](https://github.com/elm-lang/elm-platform/issues/30) I am using -an out of date version of GHC (the Haskell compiler): I have 7.6.3 (the version -that comes with Debian), and Elm wants 7.10. Fair enough: unlike a package -manager, I can see how new features in the compiler would be helpful, and when -I go back and check this was outlined in the README. Fortunately there is a new -version of GHC in the `jessie-backports` repo, so: - -<pre class="terminal"> -sudo apt install -t jessie-backports ghc -</pre> - -And now: - -<pre class="terminal"> -bnewbold@eschaton$ cabal --version -cabal-install version 1.22.6.0 -using version 1.22.5.0 of the Cabal library -bnewbold@eschaton$ ghc --version -The Glorious Glasgow Haskell Compilation System, version 7.10.3 -</pre> - -After that, I'm miraculously able to compile. Horray! I add -`~/bin/Elm-Platform/0.16/.cabal-sandbox/bin` to my `$PATH` and I can run: - -<pre class="terminal"> -bnewbold@eschaton$ elm-repl ----- elm repl 0.16.0 ----------------------------------------------------------- -:help for help, :exit to exit, more at <https://github.com/elm-lang/elm-repl> --------------------------------------------------------------------------------- -> -</pre> - -Success! - -To be clear, once I got this far I had few or no problems with Elm. The -language seems reasonably clean and well documented for it's maturity, and it -was only this install procress that felt horribly broken. - -Throughout this debugging process I had problems with both my external [Lenovo -Thinkpad USB keyboard][keyboard] glitching (workaround: unplug and re-plug) and -with WiFi at the Recurse Center disconnecting (workaround: reset wifi card). -Others here using GNU/Linux have the same wifi problems, but we don't have a -fix yet... something to do with wireless regulatory zones. - -It's not all pain though; installing the `elm.vim` syntax highlighting plugin -was very easy, just a single `git clone` into `~/.vim/bundle/`. - -[keyboard]: https://www.amazon.com/Lenovo-ThinkPad-Compact-Keyboard-TrackPoint/dp/B00F3U4TQS - -<a name="nowwhat" /> - -So Now What? ----------------- - -There was a great long-form blog post by Sam Boyer a few months ago ("[So You -Want To Write a Package Manager][5]") which describes the jumble of *system*, -*language*, and *project* dependency manager problems I experienced above. Sam -basically concludes that Rust's project/language dependency manager (Cargo) -both encapsulates best practices for dependable and reproducible builds, while -still allowing rapid evolution of a package "ecosystem". Cargo was designed by -[Yehuda Katz and Carl Lerche][6], and along with the -[crates.io](https://crates.io) archive it does sound very nice. My personal -feeling are usually that system-wide package managers (like Debian's `apt`) are -underappreciated by many young-but-not-bleeding-edge projects, but acknowledge -that there probably is also a need for higher tempo cross-platform project -dependency mangement for non-library projects (eg, desktop applications and web -apps). - -Ironically (given the difficulty I had installing it), the Elm language's -package manager has a great `diff` tool for checking that any changes in the -API conform to the [documented][8] [semantic versioning][semver] conventions. -For [example](https://gist.github.com/badboy/a302dd0c9020e5759240): - - $ elm-package diff evancz/elm-html 3.0.0 4.0.2 - Comparing evancz/elm-html 3.0.0 to 4.0.2... - This is a MAJOR change. - - ------ Changes to module Html.Attributes - MAJOR ------ - - Removed: - boolProperty : String -> Bool -> Attribute - stringProperty : String -> String -> Attribute - - - ------ Changes to module Html.Events - MINOR ------ - - Added: - type alias Options = - { stopPropagation : Bool, preventDefault : Bool } - defaultOptions : Html.Events.Options - onWithOptions : String -> Html.Events.Options -> Json.Decode.Decoder a -> (a -> Signal.Message) -> Html.Attribute - -This API change information is then used to *[programatically enforce][7]* the -semantic versioning rules for submissions to the Elm language library archive -and prevent a whole class of simple but annoying breakages due to unexpected -API changes. It can't detect *every* breaking change (eg, those which are -internal), but it can detect enough to be worth the effort. - -Another option for detecting fixing breakage is integration testing at the -package ecosystem level. Debian's [reproducible builds][repro] effort has built -out one such system, and continues to catch thousands of "failed to build from -source" (FTBFS) bugs along the way. Dan Luu's ["Everything is Broken"][danluu] -blog post (which to some degree inspired this one) mostly focused on the lack -of quality tests for many contemporary software projects, and proposed the use -of smart fuzzing and heuristically-generated tests to work around the huge -technical debt this represents. As far as I can tell there are hardly ever -automated integration tests for entire package archives; blame for dependency -problems is usually attributed to a bug in one package (instead of being seen -as a systemic failure), and such problems are seen as an unavoidable cost of -rapid and distributed development. - -I think we can do better. For example, some contemporary languages test -compiler changes for regressions against a broad snapshot of public code -written in that language; I know Go and Rust specifically do this to identify -problems before compiler releases, and the Python community occasionally runs -tests against the PyPi archive when considering syntax changes or feature -deprecations. And Debian's unstable and testing archives enforce a waiting -period so that human testers can turn up conflicts before packages can be moved -into stable or backports. I think we can and should automate these processes as -much as possible, and give direct feedback to library developers and package -maintainers when they push updates. Commercial Continuous Integration services -like Travis CI and Circle CI should offer more common target platforms (eg, ARM -architecture, more versions of distributions), and if they don't we should -build and host our own testing infrastructure. CI builds scripts should closely -match the official installation instructions for a given platform, so we catch -problems with those instructions quickly. - -We have more and more developers in the world wasting more and more days -wrangling with dependency hell, but despite that I think we're closer than ever -to taming the beast. - -[5]: https://medium.com/@sdboyer/so-you-want-to-write-a-package-manager-4ae9c17d9527 -[6]: https://mail.mozilla.org/pipermail/rust-dev/2014-March/009090.html -[7]: https://github.com/elm-lang/elm-package/blob/master/README.md#version-rules -[8]: https://github.com/elm-lang/elm-package/blob/master/README.md#publishing-updates -[semver]: http://semver.org/ -[appcheck]: http://www.linuxfoundation.org/collaborate/workgroups/lsb/linux-application-checker-getting-started -[repro]: https://tests.reproducible-builds.org/debian/reproducible.html - -<hr /> - -#### Follow up June 18th, 2016 - -A few days after writing this post, a new version of Elm (0.17) was -[released](http://elm-lang.org/blog/farewell-to-frp). The new version made some -big changes, like abandoning the [Functional Reactive Programming][frp] -paradigm. I found that many of the new tutorials weren't working with my 0.16 -install, so I tried to upgrade. After an hour or two of following the -directions above, I gave up and installed npm on a temporary Debian unstable -("sid") virtual machine. Once I added a `node` symlink to `nodejs`, I was able -to install `elm` with npm and develop remotely using `screen` and -`elm-react`. Frustrating! - -[frp]: https://en.wikipedia.org/wiki/Functional_reactive_programming - -<br /> -<center style="font-size: smaller;"> -<img src="/static/fig/status_haskell_broken.png" width="600px" /> -<br /> -Also, status.haskell.org seems to be broken again today, though -the hackage website works. -</center> - -On the plus side, my USB keyboard problem seems to have been due to the cheap -random USB cable I was using. Since replacing it I haven't had the bad -flakey-ness, though now after my laptop awakes from sleep the pointer and -keyboard work but the middle mouse button ("paste" on UNIX) does not. -Workaround: plug and unplug the whole keyboard. - |