Given your example, it's reasonable to assume some common-or-garden flight simulator, even an enormous one, will not be making changes to the same parts of the filesystem that
I know that if
yum is preoccupied by some larger transaction, then
rpm can still be used to install, upgrade, or erase packages, because
yum creates a lock that other
yum processes must respect, but
rpm does not need to.
dpkg can be used to install
.deb packages without having to negotiate with
apt, although they might be more closely integrated, in which case if you're prepared to eat the risk, go ahead and delete
/var/lib/dpkg/lock. I mean, what the heck? it's only the integrity of your entire OS package database!