Quoting Johannes Schauer (2020-11-14 00:37:14) > Quoting Trent W. Buck (2020-10-20 16:15:07) > > Per our IRC chat, I found tarfilter stuff[0] triggers a regression of old > > dash bug #606756. > > > > [0] > > https://gitlab.mister-muffin.de/josch/mmdebstrap/commit/465c0564345b456c41016abc6a4b1cb727125961 > > > > I narrowed it down with this test command: > > > > git bisect start 0.7.1 0.6.1 > > git bisect run ./mmdebstrap --quiet --mode=unshare --variant=apt > > --dpkgopt=path-exclude='/usr/share/man/*' stable /dev/null > > > > ...that relies on mmtarfilter being in $PATH, so you will need mmdebstrap > > 0.7.x package installed. > > > > Attached are some files: > > > > git-bisect.log - a log of the git bisect > > bad.log - a log of the actual error (from dpkg.postinst) > > workaround.log - a log of a minimal workaround > > tar-t.log - a log of showing the final tarball's contents with > > different commits & options > > > > I think the last one shows a clear difference between tarfilter and dpkg's > > built-in exclusions. > > I think I understand the problem now. So, the original problem is, that since > I > introduced the tarfilter command, so that packages do not need to be > re-installed when using the dpkg path-excluded option, dash fails to install > with the following error when excluding /usr/share/man/*: > > ln: failed to create symbolic link '/usr/share/man/man1/sh.1.gz.tmp': No such > file or directory > > This makes sense, because indeed the directory /usr/share/man/man1 was > excluded > and thus the symbolic link cannot be created. The question is, why did this > work before? The answer is simple: before the tarfilter, the initial package > installation was done with the /usr/share/man/man1 still present, because > before tarfilter, mmdebstrap would just extract the full package contents. > Only > the re-install step would then delete everything according to the > path-excluded > option. But at that point, the relevant part of the postinst script is not run > anymore, so there will not be a failure. > > Also, re-reading #606756 and also the dash postinst, I see nothing that is a > safeguard against a missing /usr/share/man/man1. I think I should open another > bug against dash because it clearly fails to install without > /usr/share/man/man1 present.
I can confirm that the following patch to dash fixes the problem:
--- a/debian/dash.postinst
+++ b/debian/dash.postinst
@@ -132,8 +132,10 @@ if [ $debconf ]; then
db_get dash/sh
if [ "$RET" = true ]; then
claim_binsh /bin/sh dash
+ if [ -d /usr/share/man/man1/ ]; then
claim_binsh /usr/share/man/man1/sh.1.gz dash.1.gz \
/usr/share/man/man1/sh.distrib.1.gz
+ fi
else
unclaim_binsh /bin/sh dash
unclaim_binsh /usr/share/man/man1/sh.1.gz dash.1.gz \
signature.asc
Description: signature
