Re: [PATCH] perf build: Override OUTPUT when building internal libraries

[sashiko-bot@kernel.org]

> From: Dmitry Safonov <dima@arista.com>
> 
> After commit 1572ba36fbca ("perf tests: Improvements to build-test
> performance"), building perf with OUTPUT on the command line fails:
>   make -C tools/perf OUTPUT=/tmp/linux/bld/perf/ ARCH=x86_64 LC_ALL=C CC=gcc HOSTCC=gcc LD=ld
>   ...
>   make[3]: *** No rule to make target '/tmp/linux/perf/libsubcmd/libsubcmd.a'.  Stop.
> 
> MAKEFLAGS propagates the command-line OUTPUT assignment to recursive makes.
> The library builds pass their output directories through $O, but the assignment
> to $OUTPUT in tools/scripts/Makefile.include cannot replace a command-line
> argument. This affects libapi, libperf, libsubcmd and libsymbol.
> 
> With "unexport MAKEFLAGS" returned and added $(info) debug in libsubcmd
> Makefile produces:
>   OUTPUT = /tmp/linux/perf/libsubcmd/
> Without it, on current master it prints:
>   OUTPUT = /tmp/linux/perf/
> 
> Pass OUTPUT explicitly to each library build, including the trailing slash
> required when constructing file names. This follows the existing libbpf
> build rule and preserves MAKEFLAGS and jobserver propagation.
> 
> Fixes: 1572ba36fbca ("perf tests: Improvements to build-test performance")
> Signed-off-by: Dmitry Safonov <dima@arista.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261103-perf-output-v1-1-df33a0368cf2@arista.com?part=1