cmake suddenly stopped working

[Norton Allen]

Windows 10

Cygwin installed all up to date

cmake 3.17.3-2, which does not appear to have changed since August

Symptoms: cmake fails silently with (or without) any arguments, 
including --help. Exit code is 127

I tried to reinstall cmake, the file appears to be identical

cygcheck -s and cygcheck /usr/bin/cmake both look OK to to me, though 
I'd be happy to upload if anyone is interested.

My AV is ESET. Tried disabling it to no effect.

This could have been caused by a recent cygwin update. The following 
were all installed last Friday. Would anyone like to guess which are 
worth checking? I will cross-check with the cygcheck output for cmake.

Is anyone else seeing this? Any suggestions?

    Nov 13 11:30 gdb.lst.gz
    Nov 13 11:30 git.lst.gz
    Nov 13 11:30 gcc-g++.lst.gz
    Nov 13 11:30 libsource-highlight4.lst.gz
    Nov 13 11:30 openssh.lst.gz
    Nov 13 11:29 gcc-core.lst.gz
    Nov 13 11:29 libboost_regex1.66.lst.gz
    Nov 13 11:29 make.lst.gz
    Nov 13 11:29 libfido2.lst.gz
    Nov 13 11:29 libsource-highlight-common.lst.gz
    Nov 13 11:29 libzstd1.lst.gz
    Nov 13 11:29 libisl22.lst.gz
    Nov 13 11:29 libicu61.lst.gz
    Nov 13 11:29 libguile2.2_1.lst.gz
    Nov 13 11:29 libcbor.lst.gz
    Nov 13 11:29 libjsoncpp24.lst.gz
    Nov 13 11:29 screen.lst.gz
    Nov 13 11:29 libncurses-devel.lst.gz
    Nov 13 11:29 less.lst.gz
    Nov 13 11:29 graphviz.lst.gz
    Nov 13 11:29 file.lst.gz
    Nov 13 11:29 doxygen.lst.gz
    Nov 13 11:29 cygwin-doc.lst.gz
    Nov 13 11:29 bzip2.lst.gz