make install attempts to write to /etc regardless of specified destination directory

[xiota]

Describe the bug

After successfully downloading and building the 4.2.0 source tarball, attempting to install with either make install or cmake --install produces errors.

• Errors differ depending on which command is run.
• I am setting DESTDIR to redirect output to a specified directory for packaging.
• Building with make or cmake --build build does not seem to make a difference.
• A few weeks ago, with a pre-4.2.0 git checkout (1c49926), make install was able to run, but produced the same error as running cmake --install from the tarball. A recent git checkout (cb176c3) has the same behavior.

To Reproduce

$ cmake -B build -S "hal-4.2.0" \
    -D CMAKE_BUILD_TYPE=Release \
    -D CMAKE_INSTALL_PREFIX='/usr'
...

$ cmake --build build
...

$ pkgdir="$PWD/pkg"
$ mkdir -p "$pkgdir"

$ make DESTDIR="$pkgdir" install

make: *** No rule to make target 'install'.  Stop.

$ DESTDIR="$pkgdir" cmake --install build
...

-- Copy file /usr/share/hal/ld_conf/hal.conf to /etc/ld.so.conf.d/
Error copying file "hal.conf" to "/etc/ld.so.conf.d/".
-- Running: ldconfig
ldconfig: Can't create temporary cache file /etc/ld.so.cache~: Permission denied
CMake Warning at build/post_install.cmake:11 (message):
  ldconfig failed
Call Stack (most recent call first):
  build/cmake_install.cmake:147 (include)

...

Expected behavior

• Files should be installed to DESTDIR without error.
• Files should not (attempt to) be installed outside of DESTDIR.
• make and cmake --install should behave the same.

[xiota]

make install with git checkout (cb176c3) does not have the same error as when trying to install from the 4.2.0 tarball. However, it does have the same error message as cmake --install from the tarball. I found old logs, and the same error did occur previously (pre-4.2.0 git 1c49926).

-- Copy file /usr/share/hal/ld_conf/hal.conf to /etc/ld.so.conf.d/
Error copying file "hal.conf" to "/etc/ld.so.conf.d/".
-- Running: ldconfig
ldconfig: Can't create temporary cache file /etc/ld.so.cache~: Permission denied
CMake Warning at build/post_install.cmake:11 (message):
  ldconfig failed
Call Stack (most recent call first):
  build/cmake_install.cmake:147 (include)

[xiota]

I believe the problem may be:

hal/cmake/post_install.cmake.in

Line 6 in 2ab94d2

execute_process(COMMAND ${CMAKE_COMMAND} -E copy hal.conf /etc/ld.so.conf.d/)

Perhaps changing the line to the following would fix it:

 execute_process(COMMAND ${CMAKE_COMMAND} -E copy hal.conf "$ENV{DESTDIR}/etc/ld.so.conf.d/") 

I have not tested the change because of the length of time building takes.