I *think* the following patch to pkgsrc/mk/buildlink2/gen-transform.sh
fixed it correctly, but I worry that something else will break...

Index: gen-transform.sh
===================================================================
RCS file: /cvsroot/pkgsrc/mk/buildlink2/gen-transform.sh,v
retrieving revision 1.8
diff -u -r1.8 gen-transform.sh
--- gen-transform.sh	2003/01/06 09:04:29	1.8
+++ gen-transform.sh	2003/01/10 08:03:24
@@ -33,14 +33,14 @@
 			@CAT@ >> $sedfile << EOF
 s|-$1$2[ 	]$|-$1$3 |g
 s|-$1$2$|-$1$3|g
-s|-$1$2\([^ 	"':;]*\)|-$1$3\1|g
+s|-$1$2/|-$1$3/|g
 EOF
 			;;
 		untransform)
 			@CAT@ >> $sedfile << EOF
 s|-$1$3[ 	]$|-$1$2 |g
 s|-$1$3$|-$1$2|g
-s|-$1$3\([^ 	"':;]*\)|-$1$2\1|g
+s|-$1$3/|-$1$2/|g
 EOF
 			;;
 		esac
@@ -51,6 +51,7 @@
 			@CAT@ >> $sedfile << EOF
 s|-$1$2[ 	]|-$1$3 |g
 s|-$1$2$|-$1$3|g
+s|-$1$2/|-$1$3/|g
 EOF
 			;;
 		esac
@@ -59,14 +60,14 @@
 		case "$action" in
 		transform)
 			@CAT@ >> $sedfile << EOF
-s|$2\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)[ 	]|$3\1 |g
-s|$2\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)$|$3\1|g
+s|$2/\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)[ 	]|$3/\1 |g
+s|$2/\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)$|$3/\1|g
 EOF
 			;;
 		untransform)
 			@CAT@ >> $sedfile << EOF
-s|$3\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)[ 	]|$2\1 |g
-s|$3\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)$|$2\1|g
+s|$3/\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)[ 	]|$2/\1 |g
+s|$3/\(/[^ 	"':;]*/lib[^ 	/"':;]*\.a\)$|$2/\1|g
 EOF
 			;;
 		esac
@@ -87,7 +88,7 @@
 			@CAT@ >> $sedfile << EOF
 s|$2[ 	]| |g
 s|$2$||g
-s|$2[^ 	"':;]*||g
+s|$2/[^ 	"':;]*||g
 EOF
 			;;
 		esac