Re: Why was handling of program_prefix changed?

[Akim Demaille]

| > Hmm, yeah, a separator would be better. And are $build, $host, $target 
| > really deprecated?
| 
| That's my vague impression, from looking at the code.

The documentation explains the mess about these variables:

        In Autoconf 2.13, the variables @code{build}, @code{host}, and
        @code{target} had a different semantics before and after the
        invocation of @code{AC_CANONICAL_BUILD} etc.  Now, the
        argument of @option{--build} is strictly copied into
        @code{build_alias}, and is left empty otherwise.  After the
        @code{AC_CANONICAL_BUILD}, @code{build} is set to the
        canonicalized build type.  To ease the transition, before, its
        contents is the same as that of @code{build_alias}.  Do
        @emph{not} rely on this broken feature.

There is more about this in the documentation.