store: guess the URL of failing fixed-output derivations

This is a shameless layering violation in favour of UX. It falls back
trivially to "unknown", so it's purely a UX feature.

Diagnostic sample:

```
error: hash mismatch in fixed-output derivation '/nix/store/sjfw324j4533lwnpmr5z4icpb85r63ai-x1.drv':
        likely URL: https://meow.puppy.forge/puppy.tar.gz
         specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
            got:    sha256-a1Qvp3FOOkWpL9kFHgugU1ok5UtRPSu+NwCZKbbaEro=
```

Change-Id: I873eedcf7984ab23f57a6754be00232b5cb5b02c
This commit is contained in:
jade 2024-06-27 22:43:02 -07:00
parent 5dc85e8b72
commit d92712673b
4 changed files with 27 additions and 1 deletions

View file

@ -0,0 +1,16 @@
---
synopsis: "Hash mismatch diagnostics for fixed-output derivations include the URL"
cls: [1536]
credits: [jade]
category: Improvements
---
Now, when building fixed-output derivations, Lix will guess the URL that was used in the derivation using the `url` or `urls` properties in the derivation environment.
This is a layering violation but making these diagnostics tractable when there are multiple instances of the `AAAA` hash is too significant of an improvement to pass it up.
```
error: hash mismatch in fixed-output derivation '/nix/store/sjfw324j4533lwnpmr5z4icpb85r63ai-x1.drv':
likely URL: https://meow.puppy.forge/puppy.tar.gz
specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
got: sha256-a1Qvp3FOOkWpL9kFHgugU1ok5UtRPSu+NwCZKbbaEro=
```

View file

@ -2546,9 +2546,12 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
/* Throw an error after registering the path as
valid. */
worker.hashMismatch = true;
// XXX: shameless layering violation hack that makes the hash mismatch error at least not utterly worthless
auto guessedUrl = getOr(drv->env, "urls", getOr(drv->env, "url", "(unknown)"));
delayedException = std::make_exception_ptr(
BuildError("hash mismatch in fixed-output derivation '%s':\n specified: %s\n got: %s",
BuildError("hash mismatch in fixed-output derivation '%s':\n likely URL: %s\n specified: %s\n got: %s",
worker.store.printStorePath(drvPath),
guessedUrl,
wanted.to_string(SRI, true),
got.to_string(SRI, true)));
}

View file

@ -142,6 +142,8 @@ test "$(<<<"$out" grep -E '^error:' | wc -l)" = 2
<<<"$out" grepQuiet -E "hash mismatch in fixed-output derivation '.*-x1\\.drv'"
<<<"$out" grepQuiet -vE "hash mismatch in fixed-output derivation '.*-x3\\.drv'"
<<<"$out" grepQuiet -vE "hash mismatch in fixed-output derivation '.*-x2\\.drv'"
<<<"$out" grepQuiet -E "likely URL: https://meow.puppy.forge/puppy.tar.gz"
<<<"$out" grepQuiet -vE "likely URL: https://kitty.forge/cat.tar.gz"
<<<"$out" grepQuiet -E "error: build of '.*-x[1-4]\\.drv\\^out', '.*-x[1-4]\\.drv\\^out', '.*-x[1-4]\\.drv\\^out', '.*-x[1-4]\\.drv\\^out' failed"
out="$(nix build -f fod-failing.nix -L x1 x2 x3 --keep-going 2>&1)" && status=0 || status=$?
@ -151,6 +153,9 @@ test "$(<<<"$out" grep -E '^error:' | wc -l)" = 4
<<<"$out" grepQuiet -E "hash mismatch in fixed-output derivation '.*-x1\\.drv'"
<<<"$out" grepQuiet -E "hash mismatch in fixed-output derivation '.*-x3\\.drv'"
<<<"$out" grepQuiet -E "hash mismatch in fixed-output derivation '.*-x2\\.drv'"
<<<"$out" grepQuiet -E "likely URL: https://meow.puppy.forge/puppy.tar.gz"
<<<"$out" grepQuiet -E "likely URL: https://kitty.forge/cat.tar.gz"
<<<"$out" grepQuiet -E "likely URL: \(unknown\)"
<<<"$out" grepQuiet -E "error: build of '.*-x[1-3]\\.drv\\^out', '.*-x[1-3]\\.drv\\^out', '.*-x[1-3]\\.drv\\^out' failed"
out="$(nix build -f fod-failing.nix -L x4 2>&1)" && status=0 || status=$?

View file

@ -6,6 +6,7 @@ rec {
''
echo $name > $out
'';
url = "https://meow.puppy.forge/puppy.tar.gz";
outputHashMode = "recursive";
outputHash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
};
@ -15,6 +16,7 @@ rec {
''
echo $name > $out
'';
urls = "https://kitty.forge/cat.tar.gz";
outputHashMode = "recursive";
outputHash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
};