Re: [libvirt PATCH] scripts: Fix meson-install-symlink.py overwriting existing links

By default, symlink re-creation fails if the link already exists, more specifically in case of meson-install-symlink.py: Traceback (most recent call last): File "/<path_to_libvirt_repo>/scripts/meson-install-symlink.py", line 15, in <module> os.symlink(target, link) FileExistsError: File exists: '../default.xml' -> 'default.xml' Unfortunately, Python can't mimic "ln -sf", so we have to fix this differently - create a temporary name which is then going to be used for the temporary link followed by a rename with the original link's name. Note that this solution is racy as mktemp() doesn't guarantee atomicity in link creation, so theoretically another process could come and create a file with the same name as the temporary link name, but a proper solution would be longer and not as elegant.

Signed-off-by: Erik Skultety <eskultet(a)redhat.com&gt; --- scripts/meson-install-symlink.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/scripts/meson-install-symlink.py b/scripts/meson-install-symlink.py index e38507072d..630dfc079f 100644 --- a/scripts/meson-install-symlink.py +++ b/scripts/meson-install-symlink.py @@ -2,6 +2,7 @@ import os import sys +import tempfile destdir = os.environ.get('DESTDIR', os.sep) dirname = sys.argv[1] @@ -12,4 +13,7 @@ workdir = os.path.join(destdir, dirname.strip(os.sep)) os.makedirs(workdir, exist_ok=True) os.chdir(workdir) -os.symlink(target, link) + +templink = tempfile.mktemp(dir=workdir) +os.symlink(target, templink) +os.replace(templink, link) -- 2.26.2