I'm having trouble getting cygwin bash to start up - I tried older versions of bash, and I see that other tools are crashing also. I'm looking for ideas on how to collect the useful information to begin the path to getting operation of cygwin restored. I've had it running for many years, but recently upgraded to windows 10 c:\cygwin64\bin>ver Microsoft Windows [Version 10.0.22000.120] seems like this computer ran cygwin bash probably in May of 2021. To test cygwin tools I was able to add my cygwin bin directory to the path c:\cygwin64\bin>path c:\cygwin64\bin;%PATH% though normally I start cygwin with C:\cygwin64\bin\mintty.exe -i /Cygwin-Terminal.ico - c:\cygwin64\bin>tcsh 0 [main] -csh 543 cygwin_exception::open_stackdumpfile: Dumping stack trace to tcsh.exe.stackdump c:\cygwin64\bin>fish 0 [main] fish 73 cygwin_exception::open_stackdumpfile: Dumping stack trace to fish.exe.stackdump c:\cygwin64\bin>bash 0 [main] bash 566 cygwin_exception::open_stackdumpfile: Dumping stack trace to bash.exe.stackdump c:\cygwin64\bin>zsh 0 [main] zsh 1146 cygwin_exception::open_stackdumpfile: Dumping stack trace to zsh.exe.stackdump # some shells start up c:\cygwin64\bin>ash $ exit c:\cygwin64\bin>dash $ exit # even less crashes c:\cygwin64\bin>.\date | less 1 [main] less 1907 cygwin_exception::open_stackdumpfile: Dumping stack trace to less.exe.stackdump --- on the other hand, many programs can give their initial help c:\cygwin64\bin>bash --version GNU bash, version 4.4.12(3)-release (x86_64-unknown-cygwin) Copyright (C) 2016 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software; you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. here is a sample stackdump $ wc -l *.stackdump 25 bash.exe.stackdump 9 fish.exe.stackdump 9 infocmp.exe.stackdump 18 less.exe.stackdump 9 more.exe.stackdump 28 python2.7.exe.stackdump 25 sh.exe.stackdump 33 tcsh.exe.stackdump 22 zsh.exe.stackdump 178 total $ dash $ date | more Segmentation fault (core dumped) $ cat more.exe.stackdump Exception: STATUS_ACCESS_VIOLATION at rip=003E07E8A37 rax=00000003EFB1A170 rbx=0000000000000001 rcx=000000018037C76D rdx=0000000000000001 rsi=000000018037C76D rdi=00000000FFFFC514 r8 =00000000FFFFC514 r9 =0000000000000000 r10=000000000000004D r11=00000001004053BE r12=0000000000000000 r13=00000000FFFFCDF0 r14=0000000000000000 r15=0000000000000000 rbp=0000000000000001 rsp=00000000FFFFC448 program=C:\cygwin64\bin\more.exe, pid 145, thread main cs=0033 ds=002B es=002B fs=0053 gs=002B ss=002B