meson: Fix rpath clearing #95179
meson: Fix rpath clearing #95179
Conversation
Meson allows projects to set `build_rpath` property, containing paths
that will be added during build but will be removed when installing.
When Meson removes build_rpath from `DT_RUNPATH` entry, it just writes
the shorter ␀-terminated new rpath over the old one to reduce
the risk of potentially breaking the ELF files
(when the linker does string de-duplication or something).
But this can cause much bigger problem for Nix, as it can produce
cut-in-half-by-␀ store path references.
For example, in systemd’s libudev, it was removing three `$ORIGIN`-relative paths from
$ORIGIN/../libsystemd:$ORIGIN/../basic:$ORIGIN/../shared:…␀
resulting in the following `DT_RUNPATH` entry:
…␀store/v589pqjhvxrj73g3r0xb41yr84z5pwb7-gcc-9.3.0-lib/lib␀
We previously handled this in `fix-rpath.patch` but the method we prevent
Meson from removing paths added to rpath through `NIX_LDFLAGS` was changed
during 0.55.0 update and I forgot about this second purpose of the patch.
Let’s re-add this clearing code, as it worked without issues for a long time.
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Do we target staging or master? |
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Good question, its a channel blocker after all. So I would vote for master; @FRidh |
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Good question indeed. I didn't create a new staging-next yet so we can just use that. |
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Cherry-picked to master in 74ea2b2 as this was blocking channels. Checked with other nixpkgs maintainers in |
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Good! Hydra is almost done rebuilding anyway. To clarify why I put it in staging-next. Critical fixes can go directly to master, although that of course means during a day or so people will have to build a lot themselves so if its not critical its not preferred. In this case, staging-next was inactive (it was just merged into master, hence the failure), so pushing it there allows Hydra to build everything without affecting master users. |
Motivation for this change
Meson allows projects to set
build_rpathproperty, containing paths that will be added during build but will be removed when installing.When Meson removes build_rpath from
DT_RUNPATHentry, it just writes the shorter ␀-terminated new rpath over the old one to reduce the risk of potentially breaking the ELF files (when the linker does string de-duplication or something). But this can cause much bigger problem for Nix, as it can produce cut-in-half-by-␀ store path references.For example, in systemd’s libudev, it was removing three
$ORIGIN-relative paths fromresulting in the following
DT_RUNPATHentry:We previously handled this in
fix-rpath.patchbut the method we prevent Meson from removing paths added to rpath throughNIX_LDFLAGSwas changed during 0.55.0 update and I forgot about this second purpose of the patch.Let’s re-add this clearing code, as it worked without issues for a long time.
Closes: #95163
Things done
sandboxinnix.confon non-NixOS linux)systemdwith this patch andreadelf -x .dynstr result-lib/lib/libudev.soseems to be ␀-ed out properlynix-shell -p nixpkgs-review --run "nixpkgs-review wip"./result/bin/)nix path-info -Sbefore and after)