Something seems a bit odd with pipes after main-n278435-945ba658d803

As "problems" go, this is quite mild -- but it seems rather unexpected,
and thus may be an idicator of something not quite going as intended.

I am "tracking" head daily; up to main-n278435-945ba658d803 (built
Friday, 04 July), pipe behavior seemed ... normal.

Yesterday (Sunday, 06 July), running main-n278483-476d2d8f290f, I
noticed that running a "tail -F | grep ..." on the build typescript
no longer showed "interesting" excerpts of the build... until the build
was done (and script had closed the typescript file).

Or ... if (from a different terminal/window/...) I run the same
"grep" command directly against the typescript file (vs. the "tail
-F" pipeline), the earlier one (using "tail -F") "wakes up" &
displays the extracted lines up to that point.  If there is more to be
displayed, it won't be -- unless I re-run a command that reads the file
or script closes it.  (Running "grep" is not necessary -- I just tried
merely running "cat" against it; that also worked to "wake up" the "tail
-F" pipeline.)

This morning, running main-n278488-afd5bc630930, that behavior (from
yesterday) persists.  (I wanted to see if the issue persisted before
whining about it.)

The same hardware running stable/14 behaves as have systems I have run
since a couple of decades ago (in that respect).

The systems on which I have observed this are each amd64, using files on
UFS.

Additional information (build logs; dmesg; &c.) is available at
https://www.catwhisker.org/~david/FreeBSD/history/

Peace,
david
-- 
David H. Wolfskill                              david@catwhisker.org
"The whole idea of reciprocal tariffs is if someone's punching me in the
face, I'm going to punch myself in the face." -- Warwick McKibbin

See https://www.catwhisker.org/~david/publickey.gpg for my public key.