Fix handling of duplicate dependencies #902
Open
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Duplicates in resolved dependencies are uncommon, but one such case is
ffmpeg
andlibswscale-dev
, where both depend on thelibswscale-dev
apt package. Trying to install them simultaneously fails withThis appears to be caused by
debian._read_apt_cache_showpkg()
assuming a roughly one-to-one correspondence between thepackages
input list and the output lines fromapt-cache showpkg
. Due to the latter ignoring any duplicates, the resulting list of dependencies to be installed gets corrupted and some of them will fail to be installed.As a fix, this PR removes any duplicates in the list of resolved dependencies (without affecting the order).