unikernel/duniverse/dune_/test/blackbox-tests/test-cases/github3490.t

@@ -0,0 +1,25 @@
+Dune can process large amounts of process output.
+This happens in particular when diffs are processed.
+
+  $ echo '(lang dune 2.1)' > dune-project
+
+  $ cat > dune <<EOF
+  > (rule
+  >  (with-stdout-to test.corrected
+  >   (bash "for i in {1..300000}; do echo $i; done")))
+  > (rule
+  >  (alias runtest)
+  >  (action (diff test test.corrected)))
+  > EOF
+
+  $ touch test
+
+`test` is empty, and `test.corrected` contains many lines. So the diff is long.
+
+We have to pass `--diff-command` because otherwise the output is suppressed in
+the test suite; but we do not need to print it so we can grep it out
+(redirecting stderr to /dev/null would also silence the stack overflow message).
+
+  $ dune runtest --diff-command 'diff -u' 2>&1 | grep -v + | grep -v diff | grep -v "^--- test"
+  File "test", line 1, characters 0-0:
+  ...TRUNCATED BY DUNE...