Slow cygwin command waiting for cygcons.input.mutex.0

[Derek Pagel]

I have been able to replicate Cygwin commands hanging on a Windows 2019 server by running a program that loops through cp, mv, chmod and rm 100 times every 15 mins. I'm also running each of those Cygwin commands through a Microsoft utility that reports which specific Windows API a thread has called when it's stuck. Eventually, I captured this output on the chmod command from that tool:

Process 0x1c34 - chmod.exe
----------------------------------
8080: [1c34:1f90:b]->[Mutex:\BaseNamedObjects\cygwin1S5-144f71ebfd861cae\cygcons.input.mutex.0]->[1c34:160c:r]->[End]
7384: [1c34:1cd8:b]->[End]
5644: [1c34:160c:r]->[End]

It looks like it's waiting for some sort of input from somewhere. Has anyone seen anything like this?