Weird interactions between portage and autofs

[Ant P.]

Lately I've been having sporadic failures when running emerge: sometimes linux-info.eclass complains it can't find my kernel source, or I burn hours of CPU time only to have Firefox's src_install fail right at the end with a nonsensical message about too many levels of symlink recursion. When I go to inspect the wreckage, the file it errored on looks normal.

I have both /usr/src and $PORTDIR on autofs NFS mounts, and if I have terminal windows open sitting in them to prevent them unmounting, the problems never happen. It seems weird that it only started happening recently (the last few weeks/months) though - is this happening to anyone else?

[Ant P.]

The only workaround I've found for this so far is to put timeout=0 (indefinite) in autofs.conf. I tried adding "browse" to the map options, but having the paths visible isn't enough to keep portage happy.