Update:
Just to verify my assumptions, I relinked my libpgtcl.so with linker
option "-static" and mentioned all the kerberos libraries on the
commandline.
Then libpgtcl.so grew from 30kB to 1500kB, it contains now all the
stuff from tcl and from libpq and from kerberos.
And now it works.
I do not think this is a good solution. So if anybody here who is
experienced with Tcl can point me to the way how this could be done
in a cleanly fashion, that would be great.
PMc