kbuild: install-extmod-build: Fix when given dir outside the build dir

Commit b5e395653546 ("kbuild: install-extmod-build: Fix build when
specifying KBUILD_OUTPUT") tried to address the "build" variable
expecting a relative path by using `realpath --relative-base=.`, but
this only works when the given directory is below the current directory.
`realpath --relative-to=.` will return a relative path in all cases.

Fixes: b5e395653546 ("kbuild: install-extmod-build: Fix build when specifying KBUILD_OUTPUT")
Signed-off-by: James Le Cuirot <chewi@gentoo.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251016091417.9985-1-chewi@gentoo.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

diff --git a/scripts/package/install-extmod-build b/scripts/package/install-extmod-build
index b96538787f3d9f2fd22f62a471c5cb5804862c95..054fdf45cc37a8717444b8094daf3e1150a8ccf5 100755 (executable)
--- a/scripts/package/install-extmod-build
+++ b/scripts/package/install-extmod-build
@@ -63,7 +63,7 @@ if [ "${CC}" != "${HOSTCC}" ]; then
        # Clear VPATH and srcroot because the source files reside in the output
        # directory.
        # shellcheck disable=SC2016 # $(MAKE) and $(build) will be expanded by Make
-       "${MAKE}" run-command KBUILD_RUN_COMMAND='+$(MAKE) HOSTCC='"${CC}"' VPATH= srcroot=. $(build)='"$(realpath --relative-base=. "${destdir}")"/scripts
+       "${MAKE}" run-command KBUILD_RUN_COMMAND='+$(MAKE) HOSTCC='"${CC}"' VPATH= srcroot=. $(build)='"$(realpath --relative-to=. "${destdir}")"/scripts
 
        rm -f "${destdir}/scripts/Kbuild"
 fi