FreeBSD fchdir(2) changes the working directory to the directory referenced by a descriptor. The guest imports fchdir from libkernel_sys (PPSA99764, issue #1578) and the module did not export it.
The descriptor's directory is resolved from the path recorded when the directory was opened on Windows, and from the /proc/self/fd link target on Linux. The guest working directory is then set through the libc routine shared with chdir. A descriptor that is not open returns EBADF and one that is not a directory returns ENOTDIR.
AI-assisted: yes
(cherry picked from commit 76329cbb08781e13d757c3ff955acf71f8bd506f)
Adrià
Hannah Lyons
Dani
Tharun Balaji
Adrià Franch