Hooking, recording or playback may fail when using Squish 5.1.4 or newer and Qt 5 on Linux/Unix if Qt was built with the so-called gold linker. The gold linker unfortunately breaks the Squish's hooking mechanism, but no meaningful squishserver output will show up. Instead, you will recognize squishserver messages that indicate that loading of Qt symbols and instrumentation works without problem although the application can't be started or recording or playback fails.
To avoid the problem, it is currently needed to build Qt without the gold linker. This can be achieved by re-building Qt and passing the option
-no-use-gold-linker to configure.