If the user gives us a override or command-line argument that we cannot
obey, like --filesystem=/usr/share/whatever or
--filesystem=/run/flatpak/whatever, then it's confusing that we silently
ignore it. We should give them an opportunity to see that their override
was ineffective.
However, there are a few situations where we still want to keep quiet.
If there is a --filesystem argument for something that simply doesn't
exist, we don't diagnose the failure to share it: that avoids creating
unnecessary noise for apps that opportunistically share locations that
might or might not exist, like the way the Steam app on Flathub asks
for access to $XDG_RUNTIME_DIR/app/com.discordapp.Discord.
Similarly, if we have been asked for --filesystem=host, the root
directory is very likely to contain symlinks into a reserved path, like
/lib -> usr/lib. We don't need a user-visible warning for that.
We actually use the equivalent of g_message() rather than g_warning(),
to avoid this being fatal during unit testing (in particular when we
do a `flatpak info` on an app that has never been run, which will
be unable to share its `.var/app` subdirectory). `app/flatpak-main.c`
currently displays them as equivalent to each other anyway.
Signed-off-by: Simon McVittie <smcv@collabora.com>
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