sudo make install doesn't install dependencies' man pages

[wifiprintguy]

Describe the bug
When doing a "sudo make install", one would expect the ippsample project's installable assets to be installed, and also the assets from the submodules as well. Unfortunately, for some reason the submodule's Makefile install target isn't called correctly and the man pages are not installed.

To Reproduce
Steps to reproduce the behavior:

1. Do a clean "git checkout" or "git pull" on ippsample
2. Do a "git submodule update --init --recursive" to get the submodules to pull in
3. Do a "make clean && ./configure --enable-debug && make -j && make test && sudo make install"

Expected behavior
All the assets to be installed from ippsample and its submodules will be installed, including man pages.

Observed behavior
The assets from libcups (specifically the man pages) are not installed. Curiously, cd'ing into libcups and doing a sudo make install does work, and the output from that Makefile step is different than if it is run by the ippsample Makefile...

Screenshots
If applicable, add screenshots to help explain your problem.

Version of the software
smitty@Rocinante ippsample % git log -1
commit 94d1b3e (HEAD -> master, origin/master, origin/HEAD)
Author: Michael R Sweet [email protected]
Date: Fri Feb 7 16:35:33 2025 -0500

Make sure we update the ldd cache.

System Information:

• macOS 15.3.1 (24D70)

Additional context