I've seen a flurry of Debian BTS emails around this bug, but none of them have made it clear to me what I should do about it.
In the long term, I suspect that the Autoconf macros in the apr-util package should be fixed, and that autoconf-doc should document that $@ may be changed by some macros. In the short term, I'm willing to help out, if necessary, by putting some kind of Debian-specific patch that saves and restores the positional parameters (if indeed there's a way to do that) around AC_CANONICAL_SYSTEM. What would you prefer? -- "I don't want to learn the constitution and the declaration of independence (marvelous poetry though it be) by heart, and worship the flag and believe that there is a god and the dollar is its prophet." --Maarten Wiltink in the Monastery