I know there are some who will hate this, but one tiny
change to ar (trim trailing slashes from filenames) makes
plan9's ar compatible with gcc - long filename support
not withstanding.

-Steve

Reference: /n/sources/patch/applied/ar-gcc
Date: Thu May  7 10:06:49 CES 2009
Signed-off-by: steve@quintile.net

--- /sys/src/cmd/ar.c	Thu May  7 10:04:17 2009
+++ /sys/src/cmd/ar.c	Thu May  7 10:04:14 2009
@@ -701,9 +701,12 @@
 	if(strncmp(bp->hdr.fmag, ARFMAG, sizeof(bp->hdr.fmag)))
 		phaseerr(Boffset(b));
 	strncpy(name, bp->hdr.name, sizeof(bp->hdr.name));
+	name[sizeof(name)-1] = 0;
 	cp = name+sizeof(name)-1;
 	while(*--cp==' ')
 		;
+	if (cp[0] == '/')	/* trim trailing slash from GNU archives */
+		cp[0] = '\0';
 	cp[1] = '\0';
 	file = name;
 	bp->date = strtol(bp->hdr.date, 0, 0);