default.nix assumes directory is under git source control about lorri HOT 9 CLOSED

Can you elaborate on your use case?

from lorri.

@Profpatsch I use the niv tool to keep my dependencies organized. It avoids downloading the entire git repository and instead just fetches the specified rev.

I prefer this approach to manually keeping several git repositories updated, because it is reproducible and requires much less maintenance.

from lorri.

Oh, you mean src = ./.?

You can overwrite the source with an argument: nix-build …/lorri/default.nix --arg src /path/to/lorri.

from lorri.

@Profpatsch this command unfortunately fails for me.

nix-build lorri/default.nix --arg src /full/path/to/lorri

these derivations will be built:
  /nix/store/wy37hnd66xhxfd6sm9vw4p6hd95rrxpq-lorri.drv
building '/nix/store/wy37hnd66xhxfd6sm9vw4p6hd95rrxpq-lorri.drv'...
unpacking sources
unpacking source archive /nix/store/llk09dv6pvszl0gl3kzg9k96aj389615-lorri
do not know how to unpack source archive /nix/store/llk09dv6pvszl0gl3kzg9k96aj389615-lorri
builder for '/nix/store/wy37hnd66xhxfd6sm9vw4p6hd95rrxpq-lorri.drv' failed with exit code 1
error: build of '/nix/store/wy37hnd66xhxfd6sm9vw4p6hd95rrxpq-lorri.drv' failed

This is kind of my problem: There does not seem to be an obvious way to build/install lorri from a directory that isn't git version-controlled.

What does the fetchGit function achieve in default.nix?

from lorri.

You have to replace the paths by the paths you need of course.

$ wget https://github.com/target/lorri/archive/e943fa403234f1a5e403b6fdc112e79abc1e29ba.tar.gz
$ ls
default.nix  e943fa403234f1a5e403b6fdc112e79abc1e29ba.tar.gz  lorri-e943fa403234f1a5e403b6fdc112e79abc1e29ba
$  cp -r lorri-e943fa403234f1a5e403b6fdc112e79abc1e29ba/nix lorri-e943fa403234f1a5e403b6fdc112e79abc1e29ba/default.nix .
$ nix-build default.nix --arg src ./lorri-e943fa403234f1a5e403b6fdc112e79abc1e29ba --arg pkgs 'import ./nixpkgs.nix {}'

We don’t have a .git directory in the tarball, it works.

from lorri.

Interesting. Trying to build lorri seems to fail in ways that I don't fully comprehend. I suspect it might have to do with the files being stored in the nix store, or symlinking issues. (related to my personal setup)

Still, I am interested in why lorri chooses to have fetchGit in its default.nix as I have never seen that in any other nix project.
Maybe someone could explain this to me?

In any case, this is no longer relevant to the original issue.
@Profpatsch thank you for helping me, I will now close this issue.

from lorri.

Still, I am interested in why lorri chooses to have fetchGit in its default.nix as I have never seen that in any other nix project.

It’s a default argument.

let f = { a ? "foo" }: a
in f {}

will be "foo", while

let f = { a ? "foo" }: a
in f { a = "bar" }

will be "bar".

You can try it out in nix repl.

from lorri.

@Profpatsch Yes I understand that. But why would you even try to fetchGit a local directory? It doesn't make sense to me.

from lorri.

But why would you even try to fetchGit a local directory? It doesn't make sense to me.

You have to ask @grahamc ;). I agree with you that it’s not a great solution, because fetchGit caches your source for up to an hour, meaning any changes are not picked up.

from lorri.