noauto partitions, mount manually, libs not found

uxer

With defaults, stuff works.

Then, example #1:
Add noauto to /usr/X11R6 in /etc/fstab, reboot, mount /usr/X11R6 manually, launch xenodm - fails - it can't find libXdmcp.so.11.0.
Launch LD_LIBRARY_PATH=/usr/X11R6/lib xenodm - xenodm launches, but it looks like xenodm goes into restart loop - the display flashes and I can't get to any tty for longer than a fraction of a second.

Example #2:
Add noauto to /usr/local in /etc/fstab, reboot, mount /usr/local manually, launch shellcheck - fails - it can't find libffi.so.2.1.
Launch LD_LIBRARY_PATH=/usr/local/lib shellcheck - works.

Actually, I'm trying to make power losses more treatable - in /etc/fstab add noauto at column #4 and set 0 at columnt #6 for certain partitions so that base system can fsck and boot ASAP. Obviously, big separate data partition is the 1st one to become noauto and 0, but /usr/X11R6 and /usr/local seem eligible too.

Why programs stop working depending on mount time?
LD_LIBRARY_PATH seems unset by default, so programs know where to find libs without it. How do they know?
If resorting to LD_LIBRARY_PATH, what is its correct full value? I believe there must be other way than { locate '*.so'; locate '*.so.*[0-9]' ;} | while read -r FILE; do dirname "${FILE}"; done | awk '!seen[$0]++' | tr '\n' ':' - locate all .so files and take their dirnames

uxer

I have found it.
Having mounted /usr/X11R6 and /usr/local, need to do what /etc/rc does:

# Create Unix sockets directories for X if needed and make sure they have
# correct permissions.
[[ -d /usr/X11R6/lib ]] && mkdir -m 1777 /tmp/.{X11,ICE}-unix

if [[ -x /sbin/ldconfig ]]; then
        echo 'creating runtime link editor directory cache.'
        [[ -d /usr/local/lib ]] && shlib_dirs="/usr/local/lib $shlib_dirs"
        [[ -d /usr/X11R6/lib ]] && shlib_dirs="/usr/X11R6/lib $shlib_dirs"
        ldconfig $shlib_dirs
fi

Both shellcheck and xenodm (and rcctl start xenodm) now work