STM: Print/Extraction have to be skipped if -quick

Print and Extraction commands may pierce opacity: if the
task producing the proof term is not finished, we wait for
its completion.
In -quick mode no worker is going to process a task, since tasks
are simply stored to disk (and resumed later in -vio2vo mode).

This commit avoids coqc waits forever for a task in order to
Print/Extract the corresponding term.  Bug reported privately
by Alec Faithfull.

1 files changed, 10 insertions, 0 deletions

diff --git a/test-suite/vio/print.v b/test-suite/vio/print.v
new file mode 100644
index 000000000..9c36a463c
--- /dev/null
+++ b/test-suite/vio/print.v
@@ -0,0 +1,10 @@
+Lemma a : True.
+Proof.
+idtac.
+exact I.
+Qed.
+
+Print a.
+
+Lemma b : False.
+Admitted.