fetchTree: reject relative file: paths for tarballs#14983
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edolstra merged 2 commits intoNixOS:masterfrom Jan 13, 2026
Merged
fetchTree: reject relative file: paths for tarballs#14983edolstra merged 2 commits intoNixOS:masterfrom
file: paths for tarballs#14983edolstra merged 2 commits intoNixOS:masterfrom
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Relative paths like `file:./foo.tar.gz` have never worked for tarballs because curl rejects relative file: URLs. Previously this resulted in cryptic curl errors. Now we reject them early with a clear message explaining that relative paths are not supported because there is no defined base directory to resolve them against. See NixOS#12281
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file: paths for tarballs
xokdvium
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Jan 12, 2026
src/libfetchers/tarball.cc
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| "tarball '%s' uses a relative path. " | ||
| "Relative paths are not supported because the base directory is undefined. " | ||
| "Use an absolute path instead.", |
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Not sure we should call this a relative path at all, since file: scheme has no concept of base directory. Might be misleading to call it such. This phrasing makes it sound like it could be theoretically possible if the base directory were defined.
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New error:
… while fetching the input 'file:./relative-path.tar.gz'
error: tarball 'file:./relative-path.tar.gz' must use an absolute path. The 'file' scheme does not support relative paths.
Avoid implying that relative paths could work if a base directory were defined. The file: scheme fundamentally does not support them.
edolstra
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Jan 13, 2026
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Relative paths like
file:./foo.tar.gzhave never worked for tarballs because curl rejects relative file: URLs. Previously this resulted in cryptic curl errors. Now we reject them early with a clear message explaining that relative paths are not supported because there is no defined base directory to resolve them against.Motivation
Better error messages.
Intentional behavior.
Context
git+file:relative/path#12281 but easier situation.Add 👍 to pull requests you find important.
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