Cross glibc retains references to static gcc

[shlevy]

(and through it, the native stdenv)

[shlevy]

@Ericson2314 Any ideas here?

[dtzWill]

Can you give an example of what you mean? What does nix why-depends say?

[shlevy]

$ nix why-depends /nix/store/dpm7mia5w73bazhdp208qxq8k5l4wwvy-glibc-2.27-riscv64-unknown-linux-gnu/ /nix/store/rq593rsgmzl8mbx4khjx0gla3ws6nyn3-gcc-7.3.0-riscv64-unknown-linux-gnu-stage-static/
/nix/store/dpm7mia5w73bazhdp208qxq8k5l4wwvy-glibc-2.27-riscv64-unknown-linux-gnu
╚═══lib/Scrt1.o: …...................../nix/store/rq593rsgmzl8mbx4khjx0gla3ws6nyn3-gcc-7.3.0-riscv64-unknown-linux…
=> /nix/store/rq593rsgmzl8mbx4khjx0gla3ws6nyn3-gcc-7.3.0-riscv64-unknown-linux-gnu-stage-static

[Ericson2314]

Ahhh. I bet this relates to how I had to nuke more refs in make-bootstrap-tools when I combined the native and cross versions.

I'm on my phone, so try git loging that to see what I changed and then look there.

[shlevy]

@Ericson2314 Nothing obvious popping out, sorry

[dtzWill]

... why does Scrt1.o have path references/strings, anyway?

This may be specific to glibc 2.27 and/or gcc 7, which aren't used by other cross configurations... at least on master.

[dtzWill]

(this doesn't happen on, say, aarch64-musl, at least that's what I remember from poking at this last night... :))

[dtzWill]

Context for question on Scrt1.o: crt files are small (tiny! they're linked into all the things), usually defining a symbol or two .... for example on musl Scrt1 is a differently built crt1 with source like this:
https://git.musl-libc.org/cgit/musl/tree/crt/crt1.c

Hardly something you'd expect to retain the path of the compiler it was built with. I wonder if that happens with glib 2.27 on non cross or other archs?

[shlevy]

Doesn't appear to happen on non-cross based on the glibc-2.27 branch

[Ericson2314]

debug info, I'd think. Cross stuff has less stripping sometimes.

[Ericson2314]

#36948 probably also fixes this?

[goertzenator]

I ran into this in #53424 and after some experimentation landed here.

I commented out the glibc dontStrip = true line and all the extra dependencies fell away. Closure size went from 300M to 28M. So yes, it is debug info.

[lopsided98]

Do we actually need to disable stripping anymore? Tracing back through git blame and the history of the glibc package, it seems like this might have initially been added by c6b5264 in 2009 and was carried through all the updates since then. It wouldn't surprise me if it was no longer necessary, but someone should check if anything breaks.

[goertzenator]

There is a reference to cross-arm breakage, but I have no idea if that is still valid or not.

[stale]

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[lopsided98]

This was fixed by #59787.