When building an environment if two paths conflict but one or both are
symbolic links and they resolve to the same real path, the conflict is
discarded because the contents of both paths are the same. One of them
is chosen and there is no need to recur into them in order to build
deeper symbolic links.
The original change in #55372 was supposed to fix the case where a store
path which is a file should be placed into `buildEnv` which broke with a
fairly misleading Perl error.
Unfortunately this introduced a regression, `findFiles` can have targets
that are files if the file isn't a store path. Rather than adding more
obscure checks with probably further regressions, I figured that it's
better to replicate the behavior of `lib.isStorePath` and explicitly
check if the store path is a file and break in this case only.
This should also fix recent staging issues.
I noticed by creating `buildEnv` where I accidentally put a derivation
from `pkgs.writeText` into `paths` and got a broken build with the
following misleading error message:
```
Use of uninitialized value $stat1 in numeric ne (!=) at /nix/store/9g4wc31j7a2xp22xpgwr0qssfxahxdzl-builder.pl line 74.
Use of uninitialized value $stat1 in bitwise and (&) at /nix/store/9g4wc31j7a2xp22xpgwr0qssfxahxdzl-builder.pl line 75.
different permissions in `' and `/nix/store/0vy5ss91laxvwkyvrbld5hv27i88qk5w-noise': 0000 <-> 0444 at /nix/store/9g4wc31j7a2xp22xpgwr0qssfxahxdzl-builder.pl line 75.
```
It can be reproduced with an expression like this:
``` nix
{ pkgs ? import <nixpkgs> { } }:
let
file = pkgs.writeText "test" ''
content
'';
in
pkgs.buildEnv {
name = "test-env";
paths = [ /* ... */ file ];
}
```
This patch fixes#16614 and #16741.
The first issue was caused by the fact that both `/share` and
`/share/fish/vendor_completions.d` end in the `pathsToLink`. The
`pkgs/build-support/buildenv/builder.pl` creates `/share`, then links
`/share/fish` under `/share` and then tries to create the directory
`/share/fish/vendor_completions.d` and fails because it already exists.
The simplest way to reproduce the issue is to build the next Nix
expression:
```nix
let pkgs = import <nixpkgs> { };
in pkgs.buildEnv {
name = "buildenv-issue";
paths = [
pkgs.fish
pkgs.vim
];
pathsToLink = [
"/share"
"/share/fish/vendor_completions.d"
];
}
```
The second issue is more critical and was caused by the fact findFiles
doesn't recurse deep enough. It stops at first unique directory for the
package (e.g., "/share" or even "/") and later the scripts decides it
shouldn't link it as it doesn't match pathsToLink (e.g., "/share/fish"),
so the result is empty.
The test:
```nix
let pkgs = import <nixpkgs> { };
in pkgs.buildEnv {
name = "buildenv-issue";
paths = [
pkgs.fish
pkgs.vim
];
pathsToLink = [
"/share/fish/functions"
];
}
```
or
```nix
let pkgs = import <nixpkgs> { };
in pkgs.buildEnv {
name = "buildenv-issue";
paths = [
pkgs.vim
];
pathsToLink = [
"/share"
];
}
```
Regression introduced by 4529ed1259.
I've missed this in #5096, not because of a messed up rebase as I have
guessed from a comment on #12635 but missed this in the first place.
The testing I did while working on the pull request weren't exhaustive
enough to cover this, because I haven't tested with packages that use
the propagatedUserEnvPkgs attribute.
In order to make the test a bit more exhaustive this time, let's test it
using:
nix-build -E 'with import ./. {}; buildEnv {
name = "testenv";
paths = [
pkgs.hello pkgs.binutils pkgs.libsoup pkgs.gnome3.yelp
pkgs.gnome3.totem
];
}'
And with this commit the errors no longer show up and the environment is
built correctly.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Fixes: #12635
Checking file contents is redundant in this case, because we will go
ahead anyway, regardless of whether the content is the same.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Originally wanted to include ignoreCollisions in cups-progs, but I think
it's better if we use ignoreCollisions only if there are _real_
collisions between files with different contents.
Of course, we also check whether the file permissions match, so you get
a collision if contents are the same but the permissions are different.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
