fix PermissionError due to accessing pthreads upon importing trio

[jakkdl]

quickfix for #2688

[codecov]

Codecov Report

Merging #2693 (2e233c7) into master (6d71047) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2693   +/-   ##
=======================================
  Coverage   98.84%   98.84%           
=======================================
  Files         113      113           
  Lines       16474    16475    +1     
  Branches     3004     3004           
=======================================
+ Hits        16283    16284    +1     
  Misses        134      134           
  Partials       57       57           

Impacted Files	Coverage Δ
trio/_core/_thread_cache.py	100.00% <100.00%> (ø)

[jakkdl]

CI fail is due to #2689 (comment)

[A5rocks]

I don't really know if this works cause not my kinda thing. Would be happy to merge and get a quick fix out though, just please add a news fragment!

[A5rocks]

Actually we can probably ask the original issue reporter to test this. I forgot the syntax to make pip install from a specific branch :(

[jakkdl]

ah oops, I wrote a newsfragment but looks like I forgot to add the file

[jakkdl]

@chrisbeardy would you mind installing trio from this branch and seeing if it works? https://stackoverflow.com/questions/20101834/pip-install-from-git-repo-branch

[chrisbeardy]

Yep will do, give me a day or so as away for the weekend

[chrisbeardy]

Can confirm this imports ok now "on my machine"

[jakkdl]

Can confirm this imports ok now "on my machine"

Awesome! It's the only data point we have about it not working, so that's good enough for me. Feel free to merge and maybe push out a quick bugfix release if the newsfragment looks good (otherwise just edit it directly) @A5rocks