man: add Xcode man pages to search path

Closes: https://trac.macports.org/ticket/52464 (maintainer timeout)

sysutils/man/Portfile

@@ -4,6 +4,7 @@ PortSystem 1.0
 
 name                man
 version             1.6g
+revision            1
 categories          sysutils
 platforms           darwin
 maintainers         mww
@@ -62,6 +63,15 @@ variant man_all_lang {
     configure.args-append +lang all
 }
 
+# if libxcselect is available, also add Xcode man pages to search path
+if {${os.platform} eq "darwin" && ${os.major} >= 13} {
+    variant xcode description {Look up additional man pages installed by Xcode} {
+        patchfiles-append   PR11291804-xcode.diff
+        build.env-append    LIBS=-lxcselect
+    }
+    default_variants +xcode
+}
+
 platform darwin 9 {
     patchfiles-append src__man.conf.in.diff
 }