fix(gnu.org/gcc): add libc-wrapper for end-user pkgx gcc (#8423)#13094
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fix(gnu.org/gcc): add libc-wrapper for end-user pkgx gcc (#8423)#13094tannevaled wants to merge 5 commits into
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End-user `pkgx gcc test.c` on a host without distro glibc-devel / libc6-dev couldn't find stdlib.h + crt*.o. Earlier attempts via runtime.env (pkgxdev#13084) and --with-sysroot (pkgxdev#13092) failed because both poisoned gcc's own bootstrap build. This take installs a thin POSIX-sh wrapper at {{prefix}}/bin/<tool> (modeled on the bklibcvenv pattern, brewkit#348) that: 1. resolves the sibling gnu.org/glibc bottle relative to its own install path 2. exec's the real binary (moved to libexec/gcc-wrap/) with -isystem $glibc/include + -L$glibc/lib appended 3. NO-OPs when CPATH is already set (brewkit build-context — the bootstrap gcc loop uses brewkit-composed CPATH, so injecting pkgx-glibc paths twice is unnecessary and could trigger C23 symbol mismatches like __isoc23_strtoul) Pinning gnu.org/glibc <2.38 avoids C23 symbol redirects absent on older CI/host runners; the wrapper's runtime CPATH check guards against build-time poisoning regardless. Wrappers cover gcc, g++, cpp, c++, gfortran. The existing cc -> gcc and gc++ -> c++ symlinks still resolve (now via the wrapper). The wrapper dispatches by $0 basename. Pairs with pkgxdev#13083 (multi-arch triplet symlinks). Together they should fully close pkgxdev#8423. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The runtime dep on gnu.org/glibc poisoned gcc's own bootstrap build:
brewkit exposes runtime deps via CPATH/LIBRARY_PATH during build too,
so configure-time test programs end up compiling against pkgx libc
2.34 but running on the host's ld-linux — and ld-linux finds host
libc 2.35 in the default path even with LD_LIBRARY_PATH set,
producing `cannot run C++ compiled programs`.
The wrapper itself doesn't need the dep declared — it does a runtime
sibling lookup (`bindir/../../../glibc/v*`) that no-ops if no pkgx
glibc is present. Users who want the bottled libc explicitly add it:
pkgx +gnu.org/gcc +gnu.org/glibc gcc test.c
This trades automatic resolution for a clean bootstrap. Closing
this trade-off the "right" way needs a pkgx feature to separate
runtime-only deps from build-time-injected deps.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
When the wrapper detects a sibling pkgx glibc bottle, it now also passes: -Wl,--dynamic-linker=$glibc/lib/ld-linux-*.so.* -Wl,-rpath,$glibc/lib so the produced binary's ELF interpreter (PT_INTERP) points at pkgx ld-linux. End-to-end consistency: the same libc is used at compile, link, and exec. Without this, the binary's PT_INTERP would be the host's /lib64/ld-linux-x86-64.so.2 and the kernel would load host ld-linux at exec time — even with -L pointing at pkgx libc and rpath set — mixing libc internal layouts across host/pkgx. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
When a pkgx glibc sibling is found, wrapper now also passes -nostdinc (and -nostdinc++ for g++/c++) to drop /usr/include from gcc's search path, then re-adds: - gcc's own builtin headers (lib/gcc/<triplet>/<ver>/include[+-fixed]) - libstdc++ headers for C++ tools (include/c++/<ver>[/<triplet>]) - pkgx glibc headers via -isystem Without -nostdinc, gcc still found /usr/include/stdlib.h first because -isystem only appends to the search chain — so pkgx-glibc headers were shadowed by whatever the host had. Modeled on Nix's cc-wrapper.sh (pkgs/build-support/cc-wrapper/). See pkgxdev#8423. The wrapper stays opportunistic (CPATH unset + sibling glibc), so the gcc bootstrap loop is unaffected. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The previous shape moved the real gcc binary to libexec/gcc-wrap/,
which broke gcc's relative lookup for cc1 / cc1plus / collect2 (gcc
expects them at lib/gcc/<triplet>/<version>/ relative to its OWN
location). Result: `cannot execute 'cc1': No such file or directory`
during fixincludes at make-install time.
Keep the real binary at bin/.${tool}-real (hidden by leading dot
to avoid cluttering bin/) and have bin/<tool> point at the wrapper.
cc1 lookup then resolves the same way it always did.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
Adds a thin POSIX-sh wrapper at
{{prefix}}/bin/<tool>(gcc, g++, cpp, c++, gfortran) that injects-isystem $glibc/include -L$glibc/libfor end-user invocations, without poisoning gcc's own bootstrap build. The real binaries are moved to{{prefix}}/libexec/gcc-wrap/. Addsgnu.org/glibc: '<2.38'+kernel.org/linux-headers: '*'as Linux deps so pkgx provisions a sibling glibc bottle the wrapper can find.Why this approach
Previous attempts at #8423:
runtime.env CPATH): clobbered brewkit's composed CPATH during gcc's own build → couldn't findgmp.h. Closed.--with-sysroot): configure-time test programs link against the bottled glibc's interp path which doesn't exist on the host →cannot run C++ compiled programs. Closed.This take avoids both pitfalls because the wrapper:
$0-relative lookup, not via baked-in configure flags<2.38to avoid C23 symbol redirects (__isoc23_*) absent on older runnersPattern is modeled on the bklibcvenv shim (brewkit#348).
Pairs with
Test plan
pkgx gcc -E -x c /dev/nullsucceeds without distro glibc-develglibc-devel,pkgx gcc test.c -o test && ./testsucceedspkgx +gnu.org/gcc cc -v 2>&1 | grep gnu.org/glibcconfirms the wrapper found the bottleif: linux)🤖 Generated with Claude Code