PowerPC binary build failure "relocation truncated to fit: R_PPC64_REL24"

[zanieb]

The build failed during linking with

libthread_local-14bdf71b2f8c428a.rlib(thread_local-14bdf71b2f8c428a.thread_local.9165f86b66b4614-cgu.0.rcgu.o): in function `thread_local::thread_id::get_slow':
          thread_local.9165f86b66b4614-cgu.0:(.text.unlikely._ZN12thread_local9thread_id8get_slow17h6b636cdf3f4cc69eE+0x250): relocation truncated to fit: R_PPC64_REL24 against symbol `__tls_get_addr' defined in .text.__tls_get_addr section in /usr/local/musl/bin/../lib/gcc/powerpc64le-unknown-linux-musl/11.2.0/../../../../powerpc64le-unknown-linux-musl/lib/libc.a(__tls_get_addr.lo)
          /home/runner/work/uv/uv/target/powerpc64le-unknown-linux-musl/release-no-lto/deps/libuv_installer-2b553695d2f31d2e.rlib(uv_installer-2b553695d2f31d2e.uv_installer.2988552f99df20af-cgu.04.rcgu.o): in function `std::sys::thread_local::native::lazy::Storage<T,D>::initialize':
          uv_installer.2988552f99df20af-cgu.04:(.text.unlikely._ZN3std3sys12thread_local6native4lazy20Storage$LT$T$C$D$GT$10initialize17hc81f5ebe44f2f56dE+0x34): relocation truncated to fit: R_PPC64_REL24 against symbol `__tls_get_addr' defined in .text.__tls_get_addr section in /usr/local/musl/bin/../lib/gcc/powerpc64le-unknown-linux-musl/11.2.0/../../../../powerpc64le-unknown-linux-musl/lib/libc.a(__tls_get_addr.lo)
          /home/runner/work/uv/uv/target/powerpc64le-unknown-linux-musl/release-no-lto/deps/libuv_installer-2b553695d2f31d2e.rlib(uv_installer-2b553695d2f31d2e.uv_installer.2988552f99df20af-cgu.10.rcgu.o): in function `rayon_core::registry::Registry::in_worker_cold':
          uv_installer.2988552f99df20af-cgu.10:(.text.unlikely._ZN10rayon_core8registry8Registry14in_worker_cold17h7266177902601b2eE+0x2c): relocation truncated to fit: R_PPC64_REL24 against symbol `__tls_get_addr' defined in .text.__tls_get_addr section in /usr/local/musl/bin/../lib/gcc/powerpc64le-unknown-linux-musl/11.2.0/../../../../powerpc64le-unknown-linux-musl/lib/libc.a(__tls_get_addr.lo)
          collect2: error: ld returned 1 exit status

ref https://github.com/astral-sh/uv/actions/runs/12265976138/job/34223179814?pr=9791

See https://stackoverflow.com/questions/10486116/what-does-this-gcc-error-relocation-truncated-to-fit-mean

[zanieb]

Attempting a fix by changing some compiler flags

• dffaf24
• 5cc4301
• 00cf29b
• 0c369b2
• e579d03
• 6f8f133 (I thought this one had to work)

In most of these, I'm just trying to get the flag past Maturin in various ways. Not sure if it's working at all; e.g., the rustc call does not include the flags

Caused by: Cargo build finished with "exit status: 101": env -u CARGO "cargo" "rustc" "--profile" "release-no-lto" "--features" "self-update" "--target" "powerpc64le-unknown-linux-musl" "--message-format" "json-render-diagnostics" "--locked" "--manifest-path" "/home/runner/work/uv/uv/crates/uv/Cargo.toml" "--bin" "uv" "--" "-C" "strip=symbols"

edit: At least in some of these it looks like I was editing the gnu job instead of the musl cross job; see #9793 (comment) instead

[zanieb]

Also tried

• Reverting the microarchitecture change (ef59b4e)
• Reverting the cc upgrade (61433bb)
• Reverting the entire cargo update commit from Run cargo update #9712 (88f637d)
• Reverting the tracing update from Update tokio-tracing monorepo #9566 (54f6618)
• Reverting the Cargo.lock file to the previous release (20b5268)
• Reverting the resolver change from Refactor unavailable metadata to shrink the resolver #9769 (c29afad)

[zanieb]

I got the compiler flags to go through, but they don't solve the issue

• -Crelocation-model=pic -Clink-args=-Wl,-z,notext (0e0fd1d)
• -Crelocation-model=pic -Clink-args=-Wl,-z,notext -Ccode-model=large" (0e0fd1d)
• -Ctarget-feature=+crt-static(3842d88)
• -Ccode-model=large (441ca34)
• -Clink-args=-Wl,-z,notls (ca8f7b0)

[zanieb]

The trace suggests some sort of interaction between uv-installer, rayon, and tracing-subscriber

[zanieb]

The cross-build Docker image (ghcr.io/rust-cross/rust-musl-cross:powerpc64le-musl) is identical

[zanieb]

I re-ran the 0.5.7 version bump CI job to see if that would still pass https://github.com/astral-sh/uv/actions/runs/12207650814 — it succeeded so sanity prevails and it is some sort of regression.

[zanieb]

I think the next step is to do a bisect, though I suspect we've just reached some threshold of complexity that the linker has problems with on powerpc.

I briefly looked at the download stats for this artifact and they're low but non-zero.

As a drastic step, I think we could turn of tracing for this target? But that seems pretty invasive.

[zanieb]

We are going to drop support for now, see #9810