The pipe's FDs got inherited by ssh and it did something that kept them
open even once it exited. Probably involving passing them on to the ssh
mux daemon.
Set close on exec, and all is well.
Kept Annex.Ssh not using processTranscript even though it no longer
hangs when it does use it, just because processTranscript is overkill
there.
This commit was supported by the NSF-funded DataLad project.
This is much clearer to follow.
I've tested this, and it still has the problem described in
doc/bugs/occasional_hang_with_p2pstdio.mdwn
Which I think indicates that problem is not with my code, but something
else. ghc runtime? Something crazy ssh does in this situation? Unsure..
Fourth or fifth try at this and finally found a way to make it work.
Absurd amount of busy-work forced on me by change in cabal's behavior.
Split up Utility modules that need posix stuff out of ones used by
Setup. Various other hacks around inability for Setup to use anything
that ifdefs a use of unix.
Probably lost a full day of my life to this.
This is how build systems make their users hate them. Just saying.
