relay: Don't BUG() if we can't find authority descriptor

We can end up trying to find our address from an authority while we don't have
yet its descriptor.

In this case, don't BUG() and just come back later.

Closes #40231

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/feature/relay/relay_find_addr.c b/src/feature/relay/relay_find_addr.c
index 9c2c8b281c..2da2328b14 100644
--- a/src/feature/relay/relay_find_addr.c
+++ b/src/feature/relay/relay_find_addr.c
@@ -198,9 +198,13 @@ relay_addr_learn_from_dirauth(void)
       return;
     }
     const node_t *node = node_get_by_id(rs->identity_digest);
-    if (BUG(!node)) {
-      /* If there is a routerstatus_t, there is a node_t thus this should
-       * never fail. */
+    if (!node) {
+      /* This can happen if we are still in the early starting stage where no
+       * descriptors we actually fetched and thus we have the routerstatus_t
+       * for the authority but not its descriptor which is needed to build a
+       * circuit and thus learn our address. */
+      log_info(LD_GENERAL, "Can't build a circuit to an authority. Unable to "
+                           "learn for now our address from them.");
       return;
     }
     extend_info_t *ei = extend_info_from_node(node, 1);