Error compiling bison

[Ian Moore]

Hi,
I'm trying to install php4 on a 4.6-Release machine. bison-1.75 is a 
dependency & it stops partway through compiling it.

Here is the output:

Making all in doc
makeinfo --no-split   -I .  `test -f 'bison.texinfo' || echo 
'./'`bison.texinfo -o bison.info
bison.texinfo:37: Unknown command `copying'.
bison.texinfo:58: Unmatched `@end'.
bison.texinfo:93: Unknown command `insertcopying'.
makeinfo: Removing output file `bison.info' due to errors; use --force 
to preserve.
*** Error code 2

Stop in /usr/ports/devel/bison/work/bison-1.75/doc.
*** Error code 1

Stop in /usr/ports/devel/bison/work/bison-1.75.
*** Error code 1

Stop in /usr/ports/devel/bison/work/bison-1.75.
*** Error code 1

Stop in /usr/ports/devel/bison.

I tried downloading and installing the package as well, but that gives 
the following error:
pkg_add /usr/ports/packages/bison-1.75_2.tgz
pkg_add: read_plist: bad command '@conflicts bison-1.8[0-9]*'

I'm guessing something in the base system is too old to handle compiling 
this port?

Cheers,
Ian