Unusual yaourt hanging

[devedge]

I'm having a problem I don't see any issues for.

Whenever I run a yaourt command that requires sudo (eg., yaourt -Syu), yaourt will hang for 8 - 15 (sometimes up to 30) seconds before prompting for a password. This 'hang' only happens the first time yaourt is called after startup, and subsequent runs are normal. I can't tell if this is something wrong with my groups, wifi, or anything else.

I've attached an strace file of the command being run. Something interesting to note is that about 97% of the processing time is spent on a wait4() system call. It's waiting on a [{WIFEXITED(s) && WEXITSTATUS(s) == 0}] call, but I can't find out why that's hanging.

• Here's the full strace, generated with
  strace -i -k -C -y -w -r -T -o strace_yaourt.txt yaourt -Syu strace_yaourt.txt

• Here's just the system calls: strace_yaourt_just_syscalls.txt

• And here's only the wait4() calls: strace_yaourt_wait4.txt
  The number at the end of the line is the amount of time spent running the command

Is this a bug or is it something wrong with my machine?
Here's the output of uname -a:
Linux arch 4.13.8-1-ARCH #1 SMP PREEMPT Wed Oct 18 11:49:44 CEST 2017 x86_64 GNU/Linux