I am almust sure the problem involves the eternal seek-on-files-with-nonstandard-newlines issue.

I suspect it involves cygwin infrastructure or libs, because I saw a related problem
when I recently updated cygwin from 1.7.33-1 to 2.3.1-1, along with all packages.

The evidence is that immediately on the update, a few bash scripts broke in subtle ways.
Bash was having trouble parsing certain kinds of complex expressions.

I eventually realized that the only scripts broken were CRLF files.
So, I simply ran them thru d2u, and the problem went away.
(I concede that all bash scripts should be LF-only, and I am keeping it that way hence.)

But that does not help me with less.exe; I depend on it to tail log and output files from Windows apps.
Sometimes, with some hassle, I can pipe them thru d2u or similar, but I cannot always do that.



I am a programmer.  I have been unusually bi-cultural, Windows and Unix, for decades.
I have been using cygwin for 20 years, but only as a user: I never develop with it.
I lurk on the mailing lists, but this is my first bug report.

I deploy cygwin by running setup.exe on one machine, then simply copying c:/cygwin (with cygwin, to preserve links)
to a bunch of other machines.
I normally do this big update every few months.
This procedure has been working fine for about 10 years.

I had not done my update for a full year.  Recently I started moving a few machines to Win10.
I had to update cygwin because of the "two-windows-when-launching-mintty-on-Win10" issue.

I mention my update procedure because it implies that my cygwin installation is never really
created anew.  So, there could be some old stuff in /etc or such places.  If you think I should,
I can clean and re-install cygwin from scratch on one machine, but that would be a hassle.



Just a note:  Cygwin is certainly the best-run large software system I use under Windows,
especially including Windows itself.  Thank you all, particularly Corinna,
for many years of quietly superb work.