The CCVS config.m4 doesn't search for the CCVS installation if DIR isn't given to --with-ccvs[=DIR], like
other options; since there is a default install dir for CCVS it seemed reasonable to hack it to do the search.
The symptom is that if =DIR isn't given then a spurious "-L" ends up on the command line and the next test down
the configure script fails with an apparently unrelated error message: in my case, the cURL tests told me to add
--with-openssl; I have a feeling this might also fix Bug #8045 (ccvs breaking mcrypt configuration).

This patch is just more-or-less copied from some of the other config.m4s:

Index: config.m4
===================================================================
RCS file: /repository/php4/ext/ccvs/config.m4,v
retrieving revision 1.8
diff -u -r1.8 config.m4
--- config.m4	2001/05/12 11:08:47	1.8
+++ config.m4	2001/05/17 01:33:25
@@ -1,26 +1,29 @@
-dnl $Id: config.m4,v 1.8 2001/05/12 11:08:47 sas Exp $
+dnl $Id: config.m4,v 1.7 2001/03/27 20:34:22 sniper Exp $
 dnl config.m4 for PHP4 CCVS Extension
 
-AC_MSG_CHECKING(CCVS Support)
-AC_ARG_WITH(ccvs,
-[  --with-ccvs[=DIR]       Compile CCVS support into PHP4. Please specify your 
-                          CCVS base install directory as DIR.],
-[
-  if test "$withval" != "no"; then
-     CCVS_DIR="$withval"
-	test -f $withval/include/cv_api.h && CCVS_INCLUDE_DIR=$withval/include
-    test -f $withval/lib/libccvs.a && CCVS_LIB_DIR=$withval/lib
+PHP_ARG_WITH(ccvs, for CCVS support,
+[  --with-ccvs[=DIR]       Include CCVS support])
 
-     	if test -n "$CCVS_DIR"; then
-		AC_MSG_RESULT(yes)
-		PHP_EXTENSION(ccvs)
-		LIBS="$LIBS -L$CCVS_LIB_DIR"
-		PHP_ADD_LIBRARY_WITH_PATH(ccvs, $CCVS_LIB_DIR)
-		PHP_ADD_INCLUDE($CCVS_INCLUDE_DIR)
-    	  else
-    	    AC_MSG_RESULT(no)
-    	  fi
-	fi
-],[
-  AC_MSG_RESULT(no)
-])
+if test "$PHP_CCVS" != "no"; then
+  if test -r $PHP_CCVS/include/cv_api.h; then
+     CCVS_DIR=$PHP_CCVS
+  else 
+    AC_MSG_CHECKING(for CCVS in default path)
+    for i in /usr/local/ccvs /usr; do
+      if test -r $i/include/cv_api.h; then
+        CCVS_DIR=$i
+        AC_MSG_RESULT(found in $i)
+      fi
+    done
+  fi
+
+  if test -z "$CCVS_DIR"; then
+    AC_MSG_RESULT(not found)
+    AC_MSG_ERROR(Please check your CCVS installation; cv_api.h should be in <ccvs_dir>/include/)
+  fi
+
+  PHP_ADD_INCLUDE($CCVS_DIR/include)
+  PHP_ADD_LIBRARY_WITH_PATH(ccvs, $CCVS_DIR/lib)
+
+  PHP_EXTENSION(ccvs)
+fi