CI: Build OpenSSL itself with RPATH set so .../bin/openssl doesn't

require correct LD_LIBRARY_PATH.

test/travis_before_linux.sh

@@ -113,6 +113,11 @@ fi
 if test -v TEST_OPENSSL3; then
     # Build the requested version of OpenSSL if it's not already
     # installed in the cached ~/root
+
+    ### temporarily clear cache
+    rm -rf $HOME/root/openssl-is-${TEST_OPENSSL3}
+    ### end
+
     if ! test -f $HOME/root/openssl-is-${TEST_OPENSSL3}; then
         # Remove any previous install.
         rm -rf $HOME/root/openssl3
@@ -122,7 +127,10 @@ if test -v TEST_OPENSSL3; then
            curl -L "https://github.com/openssl/openssl/releases/download/openssl-${TEST_OPENSSL3}/openssl-${TEST_OPENSSL3}.tar.gz" |
               tar -xzf -
            cd openssl-${TEST_OPENSSL3}
-           ./Configure --prefix=$HOME/root/openssl3 shared no-tests ${OPENSSL_CONFIG}
+           # Build with RPATH so ./bin/openssl doesn't require $LD_LIBRARY_PATH
+           ./Configure --prefix=$HOME/root/openssl3 \
+                       shared no-tests ${OPENSSL_CONFIG} \
+                       '-Wl,-rpath=$(LIBRPATH)'
            make $MFLAGS
            make install_sw
            touch $HOME/root/openssl-is-${TEST_OPENSSL3}