FYI, I have exactly the same error that dealmaker found when compiling from sources against php5.1.0RC2-dev, built on Oct 9th.

/tmp/dbg-2.11.32/dbg_cmd.c: In function 'dbg_get_context_sym_table':
/tmp/dbg-2.11.32/dbg_cmd.c:575: error: invalid lvalue in assignment
make: *** [dbg_cmd.lo] Error 1

Luis

open php_dbg.h, locate LLIST_FOREACH macros and remove (void *) from this data = (void *)&(item->data); assignment.
Seems this problem happens b'ze of gcc4.

Please note that I, too, am receiving the same errors. I have tried removing that (void *) text from that one macro as suggested, but it did not seem to work. I still receive the same error message.

Can you be a little more specific with exactly how to edit it? Perhaps a before and after example? Was I to leave the ampersand outside of the parentheses? Etc

I was able to get it working correctly by using GCC3 instead of 4...

what OS do you have with gcc3? I have Fedora4 but it comes with gcc4 only. I thought I could yum gcc3 but I don't see how.