Fedora 23 is not supported by the current version 1.8.4.1195 of PixInsight. See for example
this thread.
ldd /otp/PixInsight/bin/PixInsight
The PixInsight main executable should never be executed directly. Always use the launcher script, namely PixInsight.sh, on the bin distribution directory. This script sets several environment variables that are crucial for the normal execution of the PixInsight Core application on Linux and FreeBSD.
So the ldd command above won't provide any valid information, mainly because the LD_LIBRARY_PATH variable has not been initialized correctly. Assuming a bash shell, you can try this sequence instead:
$ cd /otp/PixInsight/bin
$ export LD_LIBRARY_PATH=./lib:.
$ ldd PixInsight
Note that everything PixInsight needs is on the bin/lib and bin distribution directories.
I found several of the Qt5 libraries missing, so I installed them using yum.
This is not guaranteed to work. PixInsight comes with its own set of Qt 5 libraries, which should never be replaced with the same libraries pertaining to a Linux distribution.
libzlib-pxi.so
liblcms-pxi.so
The same applies here. All -pxi shared objects and libraries are custom versions that cannot be replaced with system files.
We'll try to solve the current problems with Fedora 23 in the next version of PixInsight, but Fedora won't be an officially supported Linux distribution anymore. We officially recommend Red Hat Enterprise Linux 7, or its free variant, CentOS 7. Other distributions known to work without problems are Ubuntu 15.04 and Linux Mint 17.3. Fedora 22 and older also work.
