[erlang-questions] Erlang occasionally hangs at startup

[Loïc Hoguin]

Hello,

I see occasional hangs when starting the Erlang VM ("erl", regardless of 
options). It seems to occur only on some networks (seen it happen in a 
few hotels and seeing it in the appartment I rent here now; though it 
didn't happen a few weeks ago in the same place). I never see it at home 
though.

This is with 17.3.4, though I have seen it with 17.1 and also with 
versions before 17.

The hang is just before Erlang starts printing things in the shell.

"strace erl" prints a lot of things until:

   write(6, "\0", 1)                       = 1
   select(0, NULL, NULL, NULL, NULL

Then it hangs, then it prints the shell stuff:

   Erlang/OTP 17 [erts-6.2.1] [source] [64-bit] [smp:4:4] 
[async-threads:10] [hipe] [kernel-poll:false]

   Eshell V6.2.1  (abort with ^G)
   1>

According to the manual this select call waits until it receives a 
signal. Not sure what the signal it expects is or if it even hangs 
*there* though. My strace skills are pretty weak, especially with 
threaded programs, so I'm most likely missing something.

Note that I can Ctrl+C and get the menu just fine while it hangs. Not 
Ctrl+G though (as expected, since the shell isn't started yet).

Has anyone seen this before or knows how I can investigate this issue 
further?

-- 
Loïc Hoguin
http://ninenines.eu