Update src/libstore/remote-store.cc

Co-authored-by: Robert Hensing <[email protected]>
NixOS · Sep 7, 2023 · 7bef7a6 · 7bef7a6
1 parent 4926ee8
commit 7bef7a6
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
@@ -175,7 +175,10 @@ void RemoteStore::ConnectionHandle::processStderr(Sink * sink, Source * source,
         try {
             std::rethrow_exception(ex);
         } catch (const Error & e) {
-            // Ugly backwards compatibility hack.
+            // Nix versions before #4628 did not have an adequate behavior for reporting that the derivation format was upgraded.
+            // To avoid having to add compatibility logic in many places, we expect to catch almost all occurrences of the
+            // old incomprehensible error here, so that we can explain to users what's going on when their daemon is
+            // older than #4628 (2023).
             if (experimentalFeatureSettings.isEnabled(Xp::DynamicDerivations) &&
                 GET_PROTOCOL_MINOR(handle->daemonVersion) <= 35)
             {