The configure script failed on tk on several platforms. One is
given below. This did not happen on versions of R older than 1.5.0.
configure: WARNING: /opt_local/opt/tk-8.0/include/tk.h: accepted by the compiler, rejected by the preprocessor!
configure: WARNING: /opt_local/opt/tk-8.0/include/tk.h: proceeding with the preprocessor's result
This was in config.log, the command on a single line:
configure:21361: cc -E -I/opt_local/opt/readline/include
-I/opt_local/opt/tk/include -I/opt_local/opt/tcl/include
-I/opt_local/opt/jpeg6/inclu de -I/opt_local/opt/png/include
-I/opt_local/opt/ncurses/include -I/opt_local/opt/zlib/include
-I/opt_local/opt/R/include # no special path needed
-I/opt_local/opt/tcl-8.0/include conftest.c
cc: warning 485: Can't open "#".
cc: warning 485: Can't open "no".
cc: warning 485: Can't open "special".
cc: warning 485: Can't open "path".
cc: warning 485: Can't open "needed".
I had to edit tkConfig.sh to solve this problem. This line:
TK_XINCLUDES='# no special path needed'
After this fix, R was configured for tcl/tk, and the package
tcltk seems to work OK (at least on this platform).