problems with TEXINFOS

[Dan McMahill]

I'm using automake-1.9.6 and am having problems with texinfo files and a 
read only source tree.  In my generated Makefile.in, there is the 
following suffix rule:

.texi.info:
   restore=: && backupdir="$(am__leading_dot)am$$$$" && \
   am__cwd=`pwd` && cd $(srcdir) && \
   rm -rf $$backupdir && mkdir $$backupdir && \
   if ($(MAKEINFO) --version) >/dev/null 2>&1; then \
     for f in $@ address@hidden address@hidden $(@:.info=).i[0-9] 
$(@:.info=).i[0-9][0-9]; do \
       if test -f $$f; then mv $$f $$backupdir; restore=mv; else :; fi; \
     done; \
   else :; fi && \
   cd "$$am__cwd"; \
   if $(MAKEINFO) $(AM_MAKEINFOFLAGS) $(MAKEINFOFLAGS) -I $(srcdir) \
    -o $@ $<; \
   then \
     rc=0; \
     cd $(srcdir); \
   else \
     rc=$$?; \
     cd $(srcdir) && \
     $$restore $$backupdir/* `echo "./$@" | sed 's|[^/]*$$||'`; \
   fi; \
   rm -rf $$backupdir; exit $$rc


Of particular interest is it explicitly goes to the source directory 
(read only) and tries to create a backup directory there.  Obviously 
this will fail if the source directory is read only.

Suggestions?

Is this a bug or am I doing something illegal to ever trigger this rule?

Thanks
-Dan