nix log fails to find remote log owing to URL encoding

[peterwaller-arm]

Describe the bug

If you have a derivation with a + in the name, nix log <drv> fetching from a substituter will result in a 404. Under the hood, + is the URL encoding for space ( ). Nix needs to translate the filename into a URL through URL encoding when it does a query.

Steps To Reproduce

1. Copy log of derivation with + in the name to a binary cache such as S3.
2. Use nix log /nix/store/asdf-foobar+2.drv

Observe failure:

error: build log of '/nix/store/asdf-foobar+2.drv' is not available

Obvious workaround is to URL encode the filename, but that fails without trying to query the remote cache:

error: getting status of '/nix/store/asdf-foobar%2B2.drv': No such file or directory

Expected behavior

It should be possible to do 'nix log' for a derivation with + in the name.

Metadata

nix (Nix) 2.24.8

Also tested:

nix (Nix) 2.29.0pre20250403_5e19252

Additional context

Checklist

• checked latest Nix manual (source)
• checked open bug issues and pull requests for possible duplicates

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[Mic92]

Probably some fix is here required:

nix/src/libstore/binary-cache-store.cc

Line 537 in e76bbe4

auto logPath = "log/" + std::string(baseNameOf(printStorePath(path)));