From b39e403ae246e6f5a224dbdef35d35cbbb5ac54a Mon Sep 17 00:00:00 2001
From: mefyl <mefyl@gruntech.org>
Date: Tue, 14 Jul 2020 13:25:09 +0200
Subject: [PATCH] Catch Io's Sys_error too when retrieving files from cache.

	Fix issue #3627.

Signed-off-by: mefyl <mefyl@gruntech.org>
---
 src/dune/build_system.ml                      |  3 +++
 test/blackbox-tests/dune.inc                  | 13 +++++++++++
 .../test-cases/dune-cache/missing-data/run.t  | 23 +++++++++++++++++++
 3 files changed, 39 insertions(+)
 create mode 100644 test/blackbox-tests/test-cases/dune-cache/missing-data/run.t

diff --git a/src/dune/build_system.ml b/src/dune/build_system.ml
index b6d95155024..6a40174e619 100644
--- a/src/dune/build_system.ml
+++ b/src/dune/build_system.ml
@@ -1531,6 +1531,9 @@ end = struct
                     f
                 ];
               false
+            | exception Sys_error m ->
+              Log.info [ Pp.textf "error retrieving data file: %s" m ];
+              false
             | () -> true )
           | _ -> false
         in
diff --git a/test/blackbox-tests/dune.inc b/test/blackbox-tests/dune.inc
index 6ce0d3d81c7..b4a2d726fe0 100644
--- a/test/blackbox-tests/dune.inc
+++ b/test/blackbox-tests/dune.inc
@@ -458,6 +458,17 @@
    test-cases/dune-cache/dedup-direct-copy.t
    (progn (run dune-cram run run.t) (diff? run.t run.t.corrected)))))
 
+(rule
+ (alias dune-cache-missing-data)
+ (deps
+  (package dune)
+  (source_tree test-cases/dune-cache/missing-data)
+  (alias test-deps))
+ (action
+  (chdir
+   test-cases/dune-cache/missing-data
+   (progn (run dune-cram run run.t) (diff? run.t run.t.corrected)))))
+
 (rule
  (alias dune-cache-promote)
  (deps
@@ -3122,6 +3133,7 @@
   (alias dune-cache-dedup)
   (alias dune-cache-dedup-direct)
   (alias dune-cache-dedup-direct-copy)
+  (alias dune-cache-missing-data)
   (alias dune-cache-promote)
   (alias dune-cache-promote-copy)
   (alias dune-cache-promote-direct)
@@ -3419,6 +3431,7 @@
   (alias dune-cache-dedup)
   (alias dune-cache-dedup-direct)
   (alias dune-cache-dedup-direct-copy)
+  (alias dune-cache-missing-data)
   (alias dune-cache-promote)
   (alias dune-cache-promote-copy)
   (alias dune-cache-promote-direct)
diff --git a/test/blackbox-tests/test-cases/dune-cache/missing-data/run.t b/test/blackbox-tests/test-cases/dune-cache/missing-data/run.t
new file mode 100644
index 00000000000..9eb54ea99a9
--- /dev/null
+++ b/test/blackbox-tests/test-cases/dune-cache/missing-data/run.t
@@ -0,0 +1,23 @@
+Check that missing data files simply make the cached rule invalid.
+
+  $ cat > config <<EOF
+  > (lang dune 2.1)
+  > (cache enabled)
+  > (cache-duplication copy)
+  > (cache-transport direct)
+  > EOF
+  $ cat > dune-project <<EOF
+  > (lang dune 2.1)
+  > EOF
+  $ cat > dune <<EOF
+  > (rule
+  >   (deps source)
+  >   (targets target)
+  >   (action (bash "cat source source > target")))
+  > EOF
+  $ cat > source <<EOF
+  > \_o< COIN
+  > EOF
+  $ env XDG_RUNTIME_DIR=$PWD/.xdg-runtime XDG_CACHE_HOME=$PWD/.xdg-cache dune build --config-file=config target
+  $ rm -rf _build $PWD/.xdg-cache/dune/db/files/v3/
+  $ env XDG_RUNTIME_DIR=$PWD/.xdg-runtime XDG_CACHE_HOME=$PWD/.xdg-cache dune build --config-file=config target