dnsdist: Properly link with `libdl` when building with `autotools`

Depending on the system we might actually need to link with `libdl`
when our Rust library is used, and the mechanism to do that was not
properly set up when building with `autotools` (we were adding `LIBDL`
to the the libraries we need but the variable was not properly filled).
Unfortunately the systems we are exercising in our CI do not need to
explicitly link with `libdl` so we did not notice.

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>

diff --git a/pdns/dnsdistdist/configure.ac b/pdns/dnsdistdist/configure.ac
index 82d9dae2b5378e8670850e5fc8499799f2526fee..fbfd93d68e417d5ef981753b1767cf11920fb9f8 100644 (file)
--- a/pdns/dnsdistdist/configure.ac
+++ b/pdns/dnsdistdist/configure.ac
@@ -15,7 +15,9 @@ CPPFLAGS="-DDNSDIST $CPPFLAGS"
 m4_pattern_forbid([^_?PKG_[A-Z_]+$], [*** pkg.m4 missing, please install pkg-config])
 
 LT_PREREQ([2.2.2])
-LT_INIT([disable-static])
+# Rust runtime uses dlopen from its static lib
+LT_INIT([disable-static dlopen])
+AC_SUBST([LIBDL], [$lt_cv_dlopen_libs])
 
 CFLAGS="-g -O3 -Wall -Wextra -Wshadow -fvisibility=hidden $CFLAGS"
 CXXFLAGS="-g -O3 -Wall -Wextra -Wshadow -Wmissing-declarations -Wredundant-decls -fvisibility=hidden $CXXFLAGS"