Macports 2.3.3 compile fails on yosemite with fatal error: 'pthread_np.h' file not found error

[davec.bugs@…]

Macport 2.3.3 gives the following error when compiling on Yosemite:

In file included from /Users/dave/src/MacPorts-2.3.3/vendor/tcl8.5.15/unix/../generic/regcomp.c:33:
In file included from /Users/dave/src/MacPorts-2.3.3/vendor/tcl8.5.15/unix/../generic/regguts.h:36:

In file included from /Users/dave/src/MacPorts-2.3.3/vendor/tcl8.5.15/unix/../generic/regcustom.h:33:
In file included from /Users/dave/src/MacPorts-2.3.3/vendor/tcl8.5.15/unix/../generic/tclInt.h:36:
In file included from /Users/dave/src/MacPorts-2.3.3/vendor/tcl8.5.15/unix/../generic/tclPort.h:23:
./tclUnixPort.h:637:15: fatal error: 'pthread_np.h' file not found
#           include <pthread_np.h>
                    ^
1 error generated.
make[2]: *** [regcomp.o] Error 1
make[1]: *** [all-tcl] Error 2
Mk/macports.subdir.mk:9: recipe for target 'all' failed
make: *** [all] Error 1

[davec.bugs@…]

Make error output

[ryandesign (Ryan Carsten Schmidt)]

We need more information, since this works for everyone else. Could you attach a more complete log, including the entire output from the configure and make commands? Could you attach the config.log file?