Cygwin broken (WFSO failed, Can't update my handlers, Win32 error 6, ...)

human's Avatar


10 Jun, 2020 06:33 PM showing stuff like (...I may shouldn't have deleted all the broken builds...)

> 1 [fifo_reader] sh 1439 C:\cygwin64\bin\sh.exe: *** fatal error - Can't update my handlers, Win32 error 6

> 0 [exiting thread] sh 20175 C:\cygwin64\bin\sh.exe: *** fatal error - WFSO failed, Win32 error

and other similar issues since yesterday. In general they got slower over the last days...

Additional the cygwin setup says:

> This setup is version 2.900, but setup.ini claims version 2.904 is available.

Can you update the VS2015 image with an up-to-date cygwin + packages?
Or even better: update cygwin + cygwin64 on the "newer" images and make "plain" mingw available there, too (mingw is only available up to vs2015, theoretically it should be enough to copy+paste the C:\MinGW folder from the old image to the new one).

  1. Support Staff 1 Posted by Feodor Fitsner on 10 Jun, 2020 07:33 PM

    Feodor Fitsner's Avatar

    Have you tried running on Visual Studio 2019 image?

  2. 2 Posted by human on 10 Jun, 2020 08:03 PM

    human's Avatar

    Not yet, but I'll switch as shows plain MinGW only be missing from the 2017 image.

    New build is running, I'll report my findings tomorrow.

  3. 3 Posted by human on 10 Jun, 2020 08:24 PM

    human's Avatar

    Switching to VS2019 image didn't help:

    > 0 [exiting thread] sh 17303 C:\cygwin\bin\sh.exe: *** fatal error - WFSO failed, Win32 error 6

    Only change: the setup.exe is on 2.904 already.

  4. Support Staff 4 Posted by Feodor Fitsner on 11 Jun, 2020 08:44 PM

    Feodor Fitsner's Avatar

    OK, cygwin is being installed on VS 2019 with the following script: and it's basically pulling the latest on every image update with the last one occurred on May 29th:

    It would be great if you could indicate what's wrong with that script, so we can improve.

  5. 5 Posted by human on 11 Jun, 2020 08:50 PM

    human's Avatar

    The script and the install is not the issue - it also happens "now, but not earlier" with the VS2015 image.
    It currently just tends to break, if there's an issue with the setup it is other parts of the image.
    I guess you already made sure to disable stuff like the indexing service, windows defender service, user experience service (out of my mind those are the ones that like to break MinGW and Cygwin) - but it may be reasonable to check this again, along with the check if the workers get out of free space/ram for whatever reasons.

  6. Support Staff 6 Posted by Feodor Fitsner on 11 Jun, 2020 08:54 PM

    Feodor Fitsner's Avatar

    Correct, mentioned suspects are disabled on build VMs. Well, I'd recommend you to look around VM via RDP to see what's going on during the build/tests.

  7. 7 Posted by human on 03 Jul, 2020 07:29 PM

    human's Avatar

    Just to drop a "no-update" the processes still regularly fail (and I did not found the time yet to attach and inspect, but that's maybe also related to the part that I'm not so optimistic to find much).

    ... note: obviously the MinGW environment is different between the 2015 worker and the 2019 one, this is NOT documented in and was therefore unexpected.
    In my ideal world the 2019 worker would have both in different folders...

Reply to this discussion

Internal reply

Formatting help / Preview (switch to plain text) No formatting (switch to Markdown)

Attaching KB article:


Attached Files

You can attach files up to 10MB

If you don't have an account yet, we need to confirm you're human and not a machine trying to post spam.

Keyboard shortcuts


? Show this help
ESC Blurs the current field

Comment Form

r Focus the comment reply box
^ + ↩ Submit the comment

You can use Command ⌘ instead of Control ^ on Mac