Bug Starting Unity via $PATH

Hi,

when I want to start Unity via the commandline it seems that you have to always use a path component like
./Unity
/opt/Unity/Editor/Unity

however, when I want to start Unity via $PATH either by including its Directory in the $PATH or linking the Unity executable in a directoy searched by $PATH it does not start.

the Editor.log in .config/unity3d/Editor.log says the following

mono profile = '/u/halle/okona/home_at/Data/Mono/lib/mono/2.0'
Unable to load mono library from /u/halle/okona/home_at/Data/MonoEmbedRuntime (x86_64)
Failed to load mono, aborting

Obviously that is the wrong path to mono. Somehow unity seems to expect to be started with a path component.