The tty probe in AUBIT_USAGE_REPORT was written as
if test -c /dev/tty && { exec 9</dev/tty; } 2>/dev/null; then
A brace group is not a subshell - it runs in the current shell - so a
failing exec redirection terminates that shell. /dev/tty is exactly the
case where that bites: the device node exists, so test -c passes, but
opening it fails whenever the process has no controlling terminal.
So on every scripted install - Ansible, CI, a docker build - configure
printed its summary, died silently at that line, and exited 1 with no
error message. The macro's own comment promises it "can never make
configure fail", which is what it was trying to do by redirecting
stderr; the redirect hides the message but not the death.
Attempting the open in a subshell contains the failure:
if test -c /dev/tty && ( exec 9</dev/tty ) 2>/dev/null; then
Verified with setsid and no stdin: configure now reaches "Run 'make' to
build." and exits 0, and still exits 0 with a terminal present.
Also add a fourth path to the informix/esql/decimal.h probe. The three
existing ones all assume a distribution include directory - pgsql/,
postgresql/, pg/ - but with a versioned prefix such as PGDG's
/usr/pgsql-18 the headers sit directly under the include directory, so
the path relative to -I is a bare informix/esql/decimal.h. That is also
the path the HAVE_PG_INFORMIX_ESQL_DECIMAL_H branch of
a4gl_esql_postgres.h actually includes, so the check now matches what
the code does.
Worth noting for anyone reading a config.log: these header probes
reporting "no", with gcc's "fatal error: ... No such file or directory"
underneath, is what a negative AC_CHECK_HEADER looks like. It is the
test doing its job, not a build failure - and nothing in a PostgreSQL
build consumes those defines anyway, since a4gl_esql_postgres.h is
included only by lib/libsql/esqlc, which configure does not build.
