tests: run populate with /dev/null as input

The test driver runs commands in a shell whose input is the console it
talks through, /dev/hvc0, which is a terminal.  ssh -t, which
writeDeploy's allocateTTY passes for remote targets, allocates a terminal
then, and reads the console, so the deploy-*-allocateTTY scenarios of
remote and sudo targets hang.  Populate and writeDeploy read nothing, so
their input is /dev/null, and ssh allocates no terminal, as these
scenarios expect.

1 files changed, 4 insertions, 2 deletions

diff --git a/tests/vm.nix b/tests/vm.nix
index 906bb09..d7b2f60 100644
--- a/tests/vm.nix
+++ b/tests/vm.nix
@@ -150,10 +150,12 @@ in pkgs.testers.runNixOSTest {
                     run(deployer, f"sh {scenario['prepareDeployer']}")
                 run(node, f"sh {scenario['prepare']}")
                 for i, phase in enumerate(scenario["phases"]):
-                    # A hang fails the scenario, not the whole test.
+                    # A hang fails the scenario, not the whole test.  The
+                    # input is the console the test driver talks through,
+                    # a terminal, which ssh -t would take over.
                     limit = phase["interrupt"] or 600
                     status, out = deployer.execute(
-                        f"env HOME=/root {phase['env']} timeout {limit} {phase['populate']} 2>&1",
+                        f"env HOME=/root {phase['env']} timeout {limit} {phase['populate']} </dev/null 2>&1",
                         timeout=900,
                     )
                     if phase["interrupt"] is not None: