Do all httpx imports before setting _have_httpx.

This gives us the expected test skipping when httpx isn't available
or is too old, vs. the test failures that were happening before
this change.

diff --git a/dns/query.py b/dns/query.py
index d49688ddac28376875cddd663978d6bf541a9698..bd8388af418541d580ee6f68ec267de014605ca7 100644 (file)
--- a/dns/query.py
+++ b/dns/query.py
@@ -60,8 +60,13 @@ def _expiration_for_this_attempt(timeout, expiration):
 _have_httpx = False
 _have_http2 = False
 try:
+    import httpcore
+    import httpcore._backends.sync
     import httpx
 
+    _CoreNetworkBackend = httpcore.NetworkBackend
+    _CoreSyncStream = httpcore._backends.sync.SyncStream
+
     _have_httpx = True
     try:
         # See if http2 support is available.
@@ -70,12 +75,6 @@ try:
     except Exception:
         pass
 
-    import httpcore
-    import httpcore._backends.sync
-
-    _CoreNetworkBackend = httpcore.NetworkBackend
-    _CoreSyncStream = httpcore._backends.sync.SyncStream
-
     class _NetworkBackend(_CoreNetworkBackend):
         def __init__(self, resolver, local_port, bootstrap_address, family):
             super().__init__()