POSIX replacement for bash's “export -n” ?

[Charles Plessy <plessy@debian.org>]

Hello everybody,

In one of the packages I maintain, building fails when the default shell is
/bin/dash because of an “export -n” command that was not found by checkbashisms
(probably because it was hidden in a Perl script).

I would like to send a patch Upstream, but have not found a drop-in replacement
for this command, apart from someghing ugly like:

BAR=$FOO ; unset FOO ; FOO=$BAR ; unset BAR

to replace ‘export -n FOO’.

Any idea ?

Have a nice day,

-- 
Charles Plessy
Tsurumi, Kanagawa, Japan