build-rootfs: add workaround for RHEL-97826

bootc owns files in `/usr/share/doc` which are correctly marked as
documentation, but because of a bug in rpm-ostree, the subdirectories
are still installed even with `documentation: false`. This throws off
`bootc container lint`.

This is fixed in newer bootc, but not RHEL 9.6.

Work around this there by checking if documentation is turned off
whether the issue is fixed, and if not, just "pass through" the docs
into the installed target via another overlay. This then will only
activate when building RHCOS 9.6. (Also c9s currently until bootc is
rebased there.)

build-rootfs

@@ -96,12 +96,32 @@ def build_rootfs(target_rootfs, manifest_path, packages, overlays, nodocs):
             argsfile.write(f"--add-dir={overlay}\n")
         if nodocs:
             argsfile.write("--no-docs\n")
+            # temporarily work around https://issues.redhat.com/browse/RHEL-97826
+            tmpd = workaround_rhel_97826(argsfile)
         argsfile.flush()
         cache_arg = ['--cachedir=/cache'] if os.path.isdir('/cache') else []
         subprocess.check_call(["/usr/libexec/bootc-base-imagectl",
                                "--args-file", argsfile.name, "build-rootfs",
                                "--manifest", 'minimal-plus',
                                target_rootfs] + cache_arg)
+    if nodocs and tmpd is not None:
+        del tmpd
+
+
+def workaround_rhel_97826(argsfile):
+    basedir = 'usr/share/doc/bootc/baseimage/base'
+    # Detect if we have https://github.com/bootc-dev/bootc/pull/1352.
+    # This is not strictly correct because we're checking the _builder
+    # image_ which could be different from the target. In practice, we don't
+    # "cross-compose" and we're always going to be fetching equal or newer
+    # NEVRAs from the repos so this is fine.
+    if os.path.exists(f'/{basedir}/sysroot/.keepdir'):
+        return
+    print("Working around RHEL-97826", flush=True)
+    tmpd = tempfile.TemporaryDirectory()
+    shutil.copytree(f'/{basedir}', os.path.join(tmpd.name, basedir), symlinks=True)
+    argsfile.write(f'--add-dir={tmpd.name}')
+    return tmpd
 
 
 # We want to keep our passwd/group as canonical for now. We should be