[R-sig-Debian] tkrplot does not install

[Stefan Th. Gries]

Same thing:

* installing *source* package ‘tkrplot’ ...
configure: creating ./config.status
config.status: creating src/Makevars
** libs
gcc -std=gnu99 -I/usr/share/R/include -I/usr/include/tcl8.5
-I/usr/include/tcl8.5     -fpic  -O3 -pipe  -g -c tcltkimg.c -o
tcltkimg.o
tcltkimg.c:2:16: fatal error: tk.h: No such file or directory
compilation terminated.
make: *** [tcltkimg.o] Error 1