From 33c3f91885429b60cab551e761f297a640aff7d5 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Fri, 7 Sep 2018 16:35:48 +0200
Subject: [PATCH] Handle queryPathInfo() failure from substituters when
 fallback is enabled

Fixes #1990.
---
 src/libstore/build.cc       | 7 +++++++
 src/libstore/local-store.cc | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index cd37f7a3f..96ca28742 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -3682,6 +3682,13 @@ void SubstitutionGoal::tryNext()
     } catch (InvalidPath &) {
         tryNext();
         return;
+    } catch (Error & e) {
+        if (settings.tryFallback) {
+            printError(e.what());
+            tryNext();
+            return;
+        }
+        throw;
     }
 
     /* Update the total expected download size. */
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index c91dbf241..5e392c237 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -880,6 +880,11 @@ void LocalStore::querySubstitutablePathInfos(const PathSet & paths,
                     narInfo ? narInfo->fileSize : 0,
                     info->narSize};
             } catch (InvalidPath) {
+            } catch (Error & e) {
+                if (settings.tryFallback)
+                    printError(e.what());
+                else
+                    throw;
             }
         }
     }