This is an excerpt taken from a cygwin mailing list archive. Has to
do with error messages when logging in at the bash prompt after you
update cygwin. I had logged in via ssh from my OpenBSD box and got
all kinds of "command unknown" messages. Still was able to loging,
but it ticked me off. While I had been updating cygwin on the XP
box, the update had crapped out numerous times on numerous servers,
which is, from my experience, pretty much business as usual when
updating cygwin. I thought that's what had caused the problem, but
apparently I was wrong. So what's new? ;) Anyway, excerpt follows
along with link to the original post.

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quoted from original message at:

http://cygwin.com/ml/cygwin/2006-10/msg00283.html

The big deal, in my eyes, is that the one of the files that I had to
fix was /etc/profile. The timestamp on this file (prior to my fix) was
May 11, 2004 -- that would be the day I first installed cygwin on this
computer. I have not modified this from the original version.
 
Wouldn't it make sense that the default /etc/profile would work
out-of-the-box with the default bash installation?

Normally it does - the preremove/postinstall scripts of the base-files
package is supposed to update /etc/profile to match
/etc/defaults/etc/profile if it does not detect any local edits.  But this
feature of base-files may have been introduced after your original
download; in which case, you can manually copy /etc/defaults/etc/profile
over /etc/profile and you should be back to normal.

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