Could we make `st_birthtimespec` conditional, to unbreak 32-bit builds?

[barracuda156]

Fails on ppc now:

In file included from /opt/local/share/common-lisp/source/cl-cffi/grovel/common.h:6,
                 from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel.c:17:
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel.c: In function 'main':
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel.c:2774:78: error: 'struct stat' has no member named 'st_birthtimespec'; did you mean 'st_atimespec'?
 2774 |   fprintf(output, " :offset %lli)", (long long signed) offsetof(struct stat, st_birthtimespec));
      |                                                                              ^~~~~~~~~~~~~~~~
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel.c:20:7: warning: unused variable 'autotype_tmp' [-Wunused-variable]
   20 |   int autotype_tmp;
      |       ^~~~~~~~~~~~
Unhandled CFFI-GROVEL:GROVEL-ERROR in thread #<error printing a SB-THREAD:THREAD: #<PRINT-NOT-READABLE {1142F511}>>: Subprocess #<UIOP/LAUNCH-PROGRAM::PROCESS-INFO {114151A1}>
 with command ("/opt/local/bin/gcc-mp-14" "-o" "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel-tmpM0NOM18K.o" "-c" "-arch" "ppc" "-g" "-Wall" "-O2" "-fdollars-in-identifiers" "-D_XOPEN_SOURCE" "-mmacosx-version-min=10.6" "-I/opt/local/include" "-isystem/opt/local/include/LegacySupport" "-D_DARWIN_C_SOURCE" "-Wno-error=int-conversion" "-Wno-error=incompatible-pointer-types" "-fno-pie" "-fPIC" "-I/opt/local/share/common-lisp/source/cl-cffi/" "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint__grovel.c")
 exited with error code 1

Backtrace for: #<SB-THREAD:THREAD tid=267 "main thread" RUNNING {113B63E1}>
0: (SB-DEBUG::DEBUGGER-DISABLED-HOOK #<CFFI-GROVEL:GROVEL-ERROR "~a" {1142CA09}> #<unused argument> :QUIT T)
1: (SB-DEBUG::RUN-HOOK *INVOKE-DEBUGGER-HOOK* #<CFFI-GROVEL:GROVEL-ERROR "~a" {1142CA09}>)
2: (INVOKE-DEBUGGER #<CFFI-GROVEL:GROVEL-ERROR "~a" {1142CA09}>)
3: (ERROR CFFI-GROVEL:GROVEL-ERROR :FORMAT-CONTROL "~a" :FORMAT-ARGUMENTS (#<UIOP/RUN-PROGRAM:SUBPROCESS-ERROR {1142BFA9}>))
4: (CFFI-GROVEL:GROVEL-ERROR "~a" #<UIOP/RUN-PROGRAM:SUBPROCESS-ERROR {1142BFA9}>)
5: ((FLET "THUNK" :IN CFFI-GROVEL:PROCESS-GROVEL-FILE))
6: (SB-IMPL::%WITH-STANDARD-IO-SYNTAX #<FUNCTION (FLET "THUNK" :IN CFFI-GROVEL:PROCESS-GROVEL-FILE) {1000C25}>)
7: (CFFI-GROVEL:PROCESS-GROVEL-FILE #P"/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/build/source/cl-osicat/posix/basic-unixint.lisp" #P#<(SIMPLE-ARRAY CHARACTER (398)) /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osicat/cl-osicat/work/.home/.cache/common-lisp/sbcl-2.4.8-macosx-ppc32/opt/loca... {1144B947}>)
8: ((:METHOD ASDF/ACTION:PERFORM (CFFI-GROVEL::PROCESS-OP CFFI-GROVEL:GROVEL-FILE)) #<CFFI-GROVEL::PROCESS-OP > #<CFFI-GROVEL:GROVEL-FILE "osicat" "posix" "basic-unixint">) [fast-method]
9: ((SB-PCL::EMF ASDF/ACTION:PERFORM) #<unused argument> #<unused argument> #<CFFI-GROVEL::PROCESS-OP > #<CFFI-GROVEL:GROVEL-FILE "osicat" "posix" "basic-unixint">)
10: ((LAMBDA NIL :IN ASDF/ACTION:CALL-WHILE-VISITING-ACTION))
11: ((:METHOD ASDF/ACTION:PERFORM :AROUND (CFFI-GROVEL::PROCESS-OP CFFI-GROVEL::CC-FLAGS-MIXIN)) #<CFFI-GROVEL::PROCESS-OP > #<CFFI-GROVEL:GROVEL-FILE "osicat" "posix" "basic-unixint">) [fast-method]
12: ((:METHOD ASDF/ACTION:PERFORM-WITH-RESTARTS :AROUND (T T)) #<CFFI-GROVEL::PROCESS-OP > #<CFFI-GROVEL:GROVEL-FILE "osicat" "posix" "basic-unixint">) [fast-method]
13: ((:METHOD ASDF/PLAN:PERFORM-PLAN (T)) #<ASDF/PLAN:SEQUENTIAL-PLAN {12E57069}>) [fast-method]
14: ((FLET SB-C::WITH-IT :IN SB-C::%WITH-COMPILATION-UNIT))
15: ((:METHOD ASDF/PLAN:PERFORM-PLAN :AROUND (T)) #<ASDF/PLAN:SEQUENTIAL-PLAN {12E57069}>) [fast-method]
16: ((:METHOD ASDF/OPERATE:OPERATE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)) #<ASDF/OPERATE:BUILD-OP > #<ASDF/SYSTEM:SYSTEM "osicat"> :PLAN-CLASS NIL :PLAN-OPTIONS NIL) [fast-method]
17: ((SB-PCL::EMF ASDF/OPERATE:OPERATE) #<unused argument> #<unused argument> #<ASDF/OPERATE:BUILD-OP > #<ASDF/SYSTEM:SYSTEM "osicat">)
18: ((LAMBDA NIL :IN ASDF/OPERATE:OPERATE))
19: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) #<ASDF/OPERATE:BUILD-OP > #<ASDF/SYSTEM:SYSTEM "osicat">) [fast-method]
20: ((SB-PCL::EMF ASDF/OPERATE:OPERATE) #<unused argument> #<unused argument> ASDF/OPERATE:BUILD-OP OSICAT)
21: ((LAMBDA NIL :IN ASDF/OPERATE:OPERATE))
22: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) ASDF/OPERATE:BUILD-OP OSICAT) [fast-method]
23: (ASDF/SESSION:CALL-WITH-ASDF-SESSION #<FUNCTION (LAMBDA NIL :IN ASDF/OPERATE:OPERATE) {113B910D}> :OVERRIDE T :KEY NIL :OVERRIDE-CACHE T :OVERRIDE-FORCING NIL)
24: ((LAMBDA NIL :IN ASDF/OPERATE:OPERATE))
25: (ASDF/SESSION:CALL-WITH-ASDF-SESSION #<FUNCTION (LAMBDA NIL :IN ASDF/OPERATE:OPERATE) {113B908D}> :OVERRIDE NIL :KEY NIL :OVERRIDE-CACHE NIL :OVERRIDE-FORCING NIL)
26: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) ASDF/OPERATE:BUILD-OP OSICAT) [fast-method]
27: (SB-INT:SIMPLE-EVAL-IN-LEXENV (ASDF/OPERATE:OPERATE (QUOTE ASDF/OPERATE:BUILD-OP) (QUOTE OSICAT)) #<NULL-LEXENV>)
28: (EVAL (ASDF/OPERATE:OPERATE (QUOTE ASDF/OPERATE:BUILD-OP) (QUOTE OSICAT)))
29: (SB-IMPL::PROCESS-EVAL/LOAD-OPTIONS ((:EVAL . "(require \"asdf\")") (:EVAL . #<(SIMPLE-ARRAY CHARACTER (300)) (setf asdf:*central-registry* (list* (quote *default-pathname-defaults*) #p"/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lisp_cl-osi... {118B5007}>) (:EVAL . "(asdf:operate (quote asdf:build-op) (quote osicat))") (:QUIT)))
30: (SB-IMPL::TOPLEVEL-INIT)
31: ((FLET SB-UNIX::BODY :IN SB-IMPL::START-LISP))
32: ((FLET "WITHOUT-INTERRUPTS-BODY-3" :IN SB-IMPL::START-LISP))
33: (SB-IMPL::%START-LISP)

unhandled condition in --disable-debugger mode, quitting
; 
; compilation unit aborted
;   caught 1 fatal ERROR condition

st_birthtimespec is not available on 32-bit archs and perhaps prior to 10.6.

[luismbo]

Yes, I'd accept a pull request to conditionalise it.