Configure/Make bug

Configure/make bug (on a Mac) version 2.2.10

It appears from the output that configure knows that malloc.h doesn't exist
$ ./configure
...
checking malloc.h usability... no
checking malloc.h presence... no
checking for malloc.h... no
...
checking for malloc.h... (cached) no
...


But make gives:
Making all in man
gcc -DHAVE_CONFIG_H -I. -I..     -g -O2 -MT texinfo2man.o -MD -MP -MF
.deps/texinfo2man.Tpo -c -o texinfo2man.o texinfo2man.c
texinfo2man.c:3:20: error: malloc.h: No such file or directory
make[2]: *** [texinfo2man.o] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2

Removing the include of malloc.h from texinfo2man.c allows it to finish
without error.