Crash on 1809 with Cygwin's git and bash

[MisterDA]

Step 21/64 : RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true && git config --global --add safe.directory /tmp/opam-sources"
 ---> Running in 5e68a25f404f
      7 [main] bash 1291 child_copy: dll data read copy failed, 0x7FFF78439000..0x7FFF78445E30, done 0, windows pid 1896, Win32 error 299
      8 [main] bash 1290 dofork: child -1 - forked process 1896 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
/etc/profile: fork: retry: Resource temporarily unavailable
      7 [main] bash 1292 child_copy: dll data read copy failed, 0x7FFF778C9000..0x7FFF778D5E30, done 0, windows pid 2156, Win32 error 299
1034450 [main] bash 1290 dofork: child -1 - forked process 2156 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
/etc/profile: fork: retry: Resource temporarily unavailable
      6 [main] bash 1293 child_copy: dll data read copy failed, 0x7FFF778C9000..0x7FFF778D5E30, done 0, windows pid 2224, Win32 error 299
3077130 [main] bash 1290 dofork: child -1 - forked process 2224 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
/etc/profile: fork: retry: Resource temporarily unavailable
      7 [main] bash 1294 child_copy: dll data read copy failed, 0x7FFF778C9000..0x7FFF778D5E30, done 0, windows pid 2280, Win32 error 299
7107016 [main] bash 1290 dofork: child -1 - forked process 2280 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
/etc/profile: fork: retry: Resource temporarily unavailable
      7 [main] bash 1295 child_copy: dll data read copy failed, 0x7FFF778C9000..0x7FFF778D5E30, done 0, windows pid 2368, Win32 error 299
15149237 [main] bash 1290 dofork: child -1 - forked process 2368 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
/etc/profile: fork: Resource temporarily unavailable

Currently prevents both mingw and msvc builds on 1809.

[mtelvers]

This has been fixed in PR #263