[bug-mailutils] Compile failure: _PATH_UTMP undeclared

[Peter Flynn]

I'm trying to compile mailutils under SunOS 4.1.3_U1 with gcc 2.7.2.
Everything configures and compiles OK down to:

gcc -DHAVE_CONFIG_H -I. -I. -I.. -I../include -I../include/mailutils/gnu 
-I../intl -DSYSCONFDIR=\"/usr/local/etc\" -g -O2 -c utmp.c -Wp,-MD,
.deps/utmp.TPlo  -fPIC -DPIC -o .libs/utmp.lo
utmp.c:27: `_PATH_UTMP' undeclared here (not in a function)
make[3]: *** [utmp.lo] Error 1
make[3]: Leaving directory `/var/tmp/mailutils-0.3/lib'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/var/tmp/mailutils-0.3/lib'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/mailutils-0.3'
make: *** [all] Error 2
#

My C isn't good enough to understand why it fails or know how 
to fix this. Can anyone suggest a fix?

///Peter