gcc -c -O -pipe -DTCL_DBGX= -Wall -Wno-implicit-int -fno-strict-aliasing -I. -I/c/dev/ruby/rubyinstaller/temp/tcl8.4.19/unix/../generic -I/c/dev/ruby/rubyinstaller/temp/tcl8.4.19/unix -DHAVE_LIMITS_H=1 -DNO_SYS_WAIT_H=1 -DNO_DLFCN_H=1 -DHAVE_UNISTD_H=1 -DHAVE_SYS_PARAM_H=1 -DTCL_WIDE_INT_TYPE=long\ long -DHAVE_LSEEK64=1 -DHAVE_GETCWD=1 -DHAVE_OPENDIR=1 -DHAVE_STRSTR=1 -DHAVE_STRTOL=1
-DHAVE_STRTOLL=1 -DHAVE_STRTOULL=1 -DHAVE_TMPNAM=1 -DNO_GETWD=1 -DNO_WAIT3=1 -DNO_UNAME=1 -DNO_REALPATH=1 -DNO_FD_SET=1 -DHAVE_SYS_TIME_H=1 -DTIME_WITH_SYS_TIME=1 -DHAVE_TIMEZONE_VAR=1 -DNO_FSTATFS=1 -DSTDC_HEADERS=1 -Duid_t=int -Dgid_t=int -Dsocklen_t=unsigned -DNO_UNION_WAIT=1 -DHAVE_SIGNED_CHAR=1 -DHAVE_PUTENV_THAT_COPIES=1 -DTCL_SHLIB_EXT=\”\” /c/dev/ruby/rubyinstaller/temp/tcl8.4.19/unix/../generic/tclBasic.c
In file included from c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/tclPort.h:22,
from c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/tclBasic.c:23:
c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/../win/tclWinPort.h:418:1: warning: “TCL_SHLIB_EXT” redefined
:32:1: warning: this is the location of the previous definition
c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/../win/tclWinPort.h:466:1: warning: “socklen_t” redefined
:28:1: warning: this is the location of the previous definition
c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/tclBasic.c:90: error: initializer element is not constant
c:/dev/ruby/rubyinstaller/temp/tcl8.4.19/generic/tclBasic.c:90: error: (near initialization for `builtInCmds[0].objProc’)

meant “you are building it in msys using linux/configure — you actually want to use win/configure”