On 2023-08-07 08:42, Martin Wege via Cygwin wrote:
> We get a weird mkfifo failure in Cygwin on NTFS:
> 
> /usr/bin/mkfifo -m 600 x.fifo
> mkfifo: cannot set permissions of 'x.fifo': Not a directory

This error is also reproducible with default fifo permissions 666 or anything 
else, and appears to be returned by gen_full_path_at() in syscalls.cc when 
called with a fifo: see attached strace extract - underlying Windows file is 
Windows shortcut x.fifo.lnk.

> Is there a known workaround? So far named fifos cannot be created somehow.

For now, create with default permissions then chmod:

$ mkfifo x.fifo && chmod 600 x.fifo
mode of 'x.fifo' changed from 0666 (rw-rw-rw-) to 0600 (rw-------)
$ ls -glo x.fifo{,.lnk}
prw------- 1 0 Aug  7 12:07 x.fifo
prw------- 1 0 Aug  7 12:07 x.fifo.lnk
$ readshortcut -af x.fifo
Target: /usr/src/
Working Directory: /usr/src/
Arguments:
Show Command: Normal
Icon Library: /usr/src/
Icon Library Offset: 0
Description: :\0:c4:1180

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry