i read all the questions with 500 server error i could find on the net but nothing seems to solve my problem:
I installed qgis and all depending packages on a debian server. The first REQUEST=GetCapabilities worked fine and i created a qgs project file in qgis desktop on my windows workstation.
Then i moved the project file + shapefiles to the cgi-bin directory and changed the permissions to do everything for everyone.
Calling REQUEST=GetCapabilities then gave me a nice output but no layers.
The problem was I forgot to change the path to the shp files. After changing it and retrying the REQUEST=GetCapabilities i got the 500 internal server error.
In apache log it only says "premature end of script headers: qgis_mapserv.fcgi" - nothing else. no missing libary.
To make sure it wasn't something with a specific shapefile i created a project with a single raster layer and a png file. I copied both to my cgi-bin folder again. And surprise. This is working. I get my raster image displayed
I also tried to put the shapefiles into my home directory and pointed the path in the project file there --> 500
tried absolute and relative pathes in project file --> 500
Any ideas why qgis desktop is working with my shapefiles but qgis server doesn't?