Hello Agatha. Thanks for the patch.
> diff --git a/configure.ac b/configure.ac > index edd53b2bb42..46f8cbc89ff 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -2979,7 +2979,10 @@ copy_dirs= > AC_ARG_WITH([build-sysroot], > [AS_HELP_STRING([--with-build-sysroot=SYSROOT], > [use sysroot as the system root during the build])], > - [if test x"$withval" != x ; then > + [if test x"$withval" = "xyes" ; then > + AC_MSG_ERROR([--with-build-sysroot requires a path argument, > use--with-build-sysroot=path]) > + fi > + if test x"$withval" != x ; then > SYSROOT_CFLAGS_FOR_TARGET="--sysroot=$withval" > fi], > [SYSROOT_CFLAGS_FOR_TARGET=]) > > [...] > > diff --git a/gcc/configure.ac b/gcc/configure.ac > index 4e8269d03b6..afb6a0d7921 100644 > --- a/gcc/configure.ac > +++ b/gcc/configure.ac > @@ -140,7 +140,10 @@ AC_ARG_WITH([native-system-header-dir], > AC_ARG_WITH(build-sysroot, > [AS_HELP_STRING([--with-build-sysroot=sysroot], > [use sysroot as the system root during the build])], > - [if test x"$withval" != x ; then > + [if test x"$withval" = "xyes"; then > + AC_MSG_ERROR([--with-build-sysroot requires a path argument, > use--with-build-sysroot=path]) > + fi > + if test x"$withval" != x ; then > SYSROOT_CFLAGS_FOR_TARGET="--sysroot=$withval" > fi], > [SYSROOT_CFLAGS_FOR_TARGET=]) The fix LGTM. While looking at it I wondered whether there is still a need to check for an empty withval in the ACTION-IF-GIVEN section of the macro, once "yes" is discarded. According to the documentation, passing --sysroot="" to gcc will make it look for system headers and libraries in DIR/usr/include and DIR/usr/lib, where DIR="" in this case, so /usr/include and /usr/lib which I think is the default :) Probably better not to rely on that though..
