Problem adding custom.css file when working on docs.

[FluxZA]

To make a custom.css file available to the mdBooks generator I tried adding

  config.constructFiles."custom.css" = {
    relPath = "custom.css";
    content = "Test CSS";
  };

to the docs/default.nix file. It crashes the build saying

error: Cannot build '/nix/store/fb1vr1aji9b8dj7ziq8byx5ixhslv4r1-mdbook-0.5.2.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/fy9y2ciqdzn76dvlv8bbjww80g62m5fy-mdbook-0.5.2-generated
         /nix/store/vh5k0y7c353ijjb6smairshz8a60b93g-mdbook-0.5.2
       Last 2 log lines:
       > structuredAttrs is enabled
       > cp: cannot stat '': No such file or directory
       For full logs, run:
         nix log /nix/store/fb1vr1aji9b8dj7ziq8byx5ixhslv4r1-mdbook-0.5.2.drv

The full logs do not contain any additional lines. From the other uses of constructFiles in the repo I think this should work and I can't figure out what the issue is.

I know I should actually add the file to the books src dir, but I was just trying to get a basic example working first and ran into this issue.

[BirdeeHub]

ah....

config.drv.__structuredAttrs = true;

Apparently structuredAttrs disables passAsFile??

I was actually unaware of this. I thought I tested this...

nix-repl> :bl pkgs.stdenv.mkDerivation { name = "testdrv"; testfile = "test content"; passAsFile = [ "testfile" ]; buildCommand = ''cp "$testfilePath" "$out"''; }

This derivation produced the following outputs:
  ./repl-result-out -> /nix/store/nmwl3zaiwrsf1qq8pzyk04viphy1zpn9-testdrv

nix-repl>

nix-repl> :bl pkgs.stdenv.mkDerivation { name = "testdrv"; testfile = "test content"; passAsFile = [ "testfile" ]; __structuredAttrs = true; buildCommand = ''cp "$testfilePath" "$out"''; }
error: Cannot build '/nix/store/qrsp8b4a0pwfkygsmq9b283q7iycm4c2-testdrv.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/l7sgvfn1m6krp5wxjn41hyac8fd8xhg3-testdrv
       Last 2 log lines:
       > structuredAttrs is enabled
       > cp: cannot stat '': No such file or directory
       For full logs, run:
         nix log /nix/store/qrsp8b4a0pwfkygsmq9b283q7iycm4c2-testdrv.drv
[1 built (2 failed), 0.0 KiB DL]

😞

This will need to be fixed here:

nix-wrapper-modules/modules/constructFiles/module.nix

Lines 132 to 138 in 9212b9c

	constructFile = name: path: builder: /* bash */ ''
	constructFile() {
	${builder}
	}
	local sourceDrvVarToConstruct=${lib.escapeShellArg "${name}Path"}
	constructFile "''${!sourceDrvVarToConstruct}" ${lib.escapeShellArg path}
	'';

[FluxZA]

I think non-breaking changes are worth a little extra complexity.

Thanks for the interim suggestion, I will see if I can use that for now.

[BirdeeHub]

I am also going to make it so people dont have to mkdir -p "$(dirname "$2")" every time they redefine builder when I do it.

It has been annoying me and that is also technically not a breaking change.

[BirdeeHub]

#516

^ fixes the problem :)

For the mdbook module you should

  config.constructFiles."custom.css" = {
    relPath = "custom.css";
    passAsContent = true;
    content = "Test CSS";
  };

For performance but this will work too

  config.constructFiles."custom.css" = {
  relPath = "custom.css";
  content = "Test CSS";
};

[FluxZA]

Wow that was fast 🎉 thanks, I will use the first version then.

Am I correct that relpath can use config.book-out-dir (I might be misremembering the name, I don't have the code infront of me) to place the css file in the build src file?

On that note, I am 99% certain I have a fix for the sidebar. It will be a lot easier if we set the option headings on the page to use the 3rd level heading ie ### Heading as this nests the options under their modules, so we can collapse based on the module headings. Are you okay with that? It can work without it, but the JS will be more complex.

[BirdeeHub]

Yeah if it works better we can change the heading level

nix-wrapper-modules/ci/docs/per-mod/rendermd.nix

Line 83 in 87fa3a7

## `${lib.options.showOption (opt.loc or [ ])}`

^ there is where we are adding the ## atm

As long as it doesn't make them super tiny and they still show up in the sidebar, go for it.

It shouldn't change the id's of the headings, so it won't break any links.

Am I correct that relpath can use config.book-out-dir (I might be misremembering the name, I don't have the code infront of me) to place the css file in the build src file?

Nah that will place it 1 level up from that. I mean, you can still refer to that path in the book.toml file tho so, pretty sure it would still work anyway.

If you want to place it in the book dir itself that would be

https://birdeehub.github.io/nix-wrapper-modules/wrapperModules/mdbook.html#booksnamegenerated-book-subdir

Wow that was fast 🎉 thanks, I will use the first version then.

I was motivated to fix it because it was a quite stupid mistake and I was not a fan of it existing XD

[BirdeeHub]

Gonna close this discussion because it was actually a bug and now it is fixed.