tcl can't be disabled via ./configure. Tried using --disable-tcl and --without-tcl (at the same time). Finally used --with-tcl=/usr/loacl/lib (which doesn't get searched otherwise) and it worked fine then. TCL was installed from source, so perhaps this doesn't apply to most, but --without-tcl and --disable-tcl shouldn't still try to install modtcl.
Side note: the new config option (in 0.080) ServerThrottle isn't listed in the wiki.