I discovered the following bug in devel/str port on my brand new
architecture (amd64):

* String Parsing test in `make check' fails

* Example code from str(3) "Substitute Text in a String"
  the one with str_parse(var, "s/^(.+?):(.+)$/$1-%s-$2/", &new, subst);
  causes signal 11 to be delivered

Here is the backtrace of the above str_parse() call:

Program received signal SIGSEGV, Segmentation fault.
0x000000080063fe84 in str_len (
    s=0xffffffff804617d0 <Error reading address 0xffffffff804617d0: Bad address>) at str_basic.c:43
43	    while (*t++ != NUL)
#0  0x000000080063fe84 in str_len (
    s=0xffffffff804617d0 <Error reading address 0xffffffff804617d0: Bad address>) at str_basic.c:43
#1  0x00000008006447a2 in str_vformat (vbuff=0x7fffffffe6f0, 
    fmt=0x7fffffffe7d7 "s-%{2}R", ap=0x7fffffffe920) at str_format.c:886
#2  0x0000000800642b25 in str_parse_va (string=0x400a0c "foo:bar", 
    pattern=0x400a19 "s/^(.+?):(.+)$/$1-%s-$2/", ap=0x7fffffffe920)
    at str_parse.c:588
#3  0x0000000800641cb7 in str_parse (string=0x400a0c "foo:bar", 
    pattern=0x400a19 "s/^(.+?):(.+)$/$1-%s-$2/") at str_parse.c:268
#4  0x0000000000400942 in main (argc=1, argv=0x7fffffffeaa0) at tmp.c:29

the problem is that `ap' is used twice:
on str_parse.c:567 and str_parse.c:588, the first usage "exhausts" it
and makes it unusable (the actual exhaustion with va_arg is done in
str_vformat() in str_format.c).

The bug reveals itself only on amd64, it waits in ambush on i386.

How-To-Repeat: 
# uname -m
amd64

/usr/ports/devel/str# make check