builddeb: Change architecture detection fallback to use dpkg-architecture

We currently use dpkg --print-architecture, which reports the
architecture of the build machine.  We can make a better guess
than this by asking dpkg-architecture what the host architecture,
i.e. the default architecture for building packages, is.  This is
sensitive to environment variables such as CC and DEB_HOST_ARCH,
which should already be set in a cross-build environment.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index 434f0b4..389bf98 100755 (executable)
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -42,13 +42,13 @@ set_debarch() {
                fi
                ;;
        *)
-               debarch=$(dpkg --print-architecture)
+               debarch=$(dpkg-architecture -qDEB_HOST_ARCH)
                echo "" >&2
                echo "** ** **  WARNING  ** ** **" >&2
                echo "" >&2
                echo "Your architecture doesn't have its equivalent" >&2
                echo "Debian userspace architecture defined!" >&2
-               echo "Falling back to using your current userspace instead!" >&2
+               echo "Falling back to the current host architecture ($debarch)." >&2
                echo "Please add support for $UTS_MACHINE to ${0} ..." >&2
                echo "" >&2
                ;;