PKG_CHECK_MODULES: bug or I don't know something?

[Evgeniy Dushistov]

Hello.

I have something like this in configure.in:

if one_option; then
...
PKG_CHECK_MODULES(APP, lib_a)
...
elif another_option; then
...
PKG_CHECK_MODULES(APP, lib_b)
...
else
...
PKG_CHECK_MODULES(APP, lib_a)
...
fi

only first PKG_CHECK_MODULES works fine,
all other entries (if active another_option ofr example)
cause configure produce message
like this:
The pkg-config script could not be found or is too old.  Make sure it
is in your PATH or set the PKG_CONFIG environment variable to the full
path to pkg-config.

looks like `autoconf' create code to find pkg-config only once,
so all other PKG_CHECK_MODULES entries don't work correctly.

May be I just missed something and this is a feature?