On my debian system, ./configure on aglib 2.0b1 results in:
checking for tclsh... /usr/bin/tclsh
checking tcl.h usability... no
checking tcl.h presence... no
checking for tcl.h... no
/usr/bin/tclsh is a link to /etc/alternatives/tclsh,
which in turn is linked to /usr/bin/tclsh8.4
As I understand from configure.in, the header file
tcl.h is searched for in
`dirname \`dirname $TCLSH\``/include
i.e. in /usr/include???
Anyway, my tcl.h lives in /usr/include/tcl8.4 and is
therefor not found.
I am proposing to go back to the tclConfig.sh approach
as in the current CVS, and find the right include path