The rpm 4.20 release introduces the following downstream
change in /usr/lib/rpm/macros:
```
%buildroot %{_builddir}/%{NAME}-%{VERSION}-build/BUILDROOT
```
This definition is broken as rpm internally does the following
since 4.20 to calculate the buildroot:
```
char *bn = rpmExpand("%{NAME}-%{VERSION}-build", NULL);
/* Tilde and caret in paths are evil, convert to underscores */
for (char *t = bn; *t; t++) {
if (*t == '^' || *t == '~')
*t = '_';
}
```
This has broken our upstream opensuse CI builds in systemd as
we do the following to fetch the list of unpackaged files by the rpm build:
```
rpmbuild
...
--define "__check_files sh -c '$(rpm --define "_topdir /var/tmp" --eval %__check_files) | tee /tmp/unpackaged-files'"
...
```
which stopped working because the check files script tries
to look for unpackaged files in the "/var/tmp/BUILD/systemd-258~devel-build/BUILDROOT"
directory (%buildroot) whereas it should be looking in "/var/tmp/BUILD/systemd-258_devel-build/BUILDROOT".
Let's remove the %buildroot compat definition until the bug is
addressed in opensuse tumbleweed.
# TODO: Drop when the opensuse spec uses README.md instead of README.testsuite.
sed --in-place 's/README.testsuite/README.md/' "pkg/$PKG_SUBDIR${GIT_SUBDIR:+/$GIT_SUBDIR}/systemd.spec"
+# TODO: Drop when https://bugzilla.opensuse.org/show_bug.cgi?id=1236901 is resolved.
+sed '/%buildroot/d' /usr/lib/rpm/macros >macros
+mount --bind "$PWD/macros" /usr/lib/rpm/macros
+rm macros
+
build() {
IFS=
# shellcheck disable=SC2046