Hello raf, On 9/6/2026 10:33 PM, raf via Cygwin wrote:
Hi,This is on Win10. I have a seemingly impossible problem with fstatat following a symlink to a fifo. Most of the resulting struct stat correctly contains details of the fifo except for the st_mode field. It contains the type and permissions of the symlink itself. I assume I must be doing something wrong but the same code works on six other operating systems. Any idea what the cause might be? My tests relating to this have been failing for ages, and I just accepted that this wierd little case just might not work on Cygwin, but looking into it closely shows that it almost does work, just not quite. Actually, the same problem happens with stat(1), not just my program. Here's a demonstration: mkdir t cd t mkfifo fifo sleep 5 ln -s fifo symfifo stat symfifo fifo stat -L symfifo cd .. rm -r t The above commands show this ouptut: $ stat symfifo fifo File: symfifo -> fifo Size: 4 Blocks: 0 IO Block: 65536 symbolic link Device: 15518,20572 Inode: 7599824372130494 Links: 1 Access: (0777/lrwxrwxrwx) Uid: (197609/ john) Gid: (197121/ None) Access: 2026-09-07 15:25:50.209111800 +1000 Modify: 2026-09-07 15:25:50.209111800 +1000 Change: 2026-09-07 15:25:50.209111800 +1000 Birth: 2026-09-07 15:25:50.209111800 +1000 File: fifo Size: 0 Blocks: 1 IO Block: 65536 fifo Device: 0,196 Inode: 8162774325551800 Links: 1 Access: (0666/prw-rw-rw-) Uid: (197609/ john) Gid: (197121/ None) Access: 2026-09-07 15:25:49.754243600 +1000 Modify: 2026-09-07 15:25:43.732451800 +1000 Change: 2026-09-07 15:25:43.732451800 +1000 Birth: 2026-09-07 15:25:43.732451800 +1000$ stat -L symfifoFile: symfifo -> fifo Size: 4294953488 Blocks: 1 IO Block: 65536 symbolic link Device: 0,196 Inode: 8162774325551800 Links: 1 Access: (0777/lrwxrwxrwx) Uid: (197609/ john) Gid: (197121/ None) Access: 2026-09-07 15:25:53.970058800 +1000 Modify: 2026-09-07 15:25:43.732451800 +1000 Change: 2026-09-07 15:25:43.732451800 +1000 Birth: 2026-09-07 15:25:43.732451800 +1000 Note that the last command that follows the symlink states that the fifo is a "symbolic link" rather than "fifo" and permissions "0777/lrwxrwxrwx" rather than "0666/prw-rw-rw-". Is this fixable? Or is it just this pc?
I've reproduced this locally, so it's not your pc ;-). What version of Cygwin are you running on your Windows 10 machine?
I've also reproduced this on Cygwin 3.3.6, which is pretty old. You may have just run into a bug that has gone undiscovered for a long time. I'll look into investigating and patching this issue.
Thanks for the report, ..mark -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
