message: guix: use autoconf 2.71
  This allows for building with newer targets, like arm64-apple-darwin, due to
  having a newer bundled config.guess and config.sub.
diff: @@ -579,7 +579,7 @@ inspecting signatures in Mach-O binaries.")
  ;; Build tools
  gnu-make
  libtool
  - autoconf
  + autoconf-2.71
  automake
  pkg-config
  bison
  