tests: wait for the thing, don't sleep and hope

test_trace_ui spent 18.8 of its 35.2 seconds in flat pilot.pause() calls placed
to let an async seek land. Two loops were most of it: 6 iterations at 0.5s and
28 at 0.3s, 11.4s of sleeping to check that a step moves the cursor.

They are condition waits now. The questions are unchanged -- does the listing
cursor reach the pc, does the pseudocode cursor follow -- but they cost what
they cost instead of a fixed budget. The second loop settles on something that
does NOT presuppose the answer (the listing cursor arriving, and the trail map
belonging to the loaded function): waiting on 'is this pc mapped' would have
burned the timeout on every unmapped instruction, about half of them, and come
out slower than the sleep it replaced.

35.2s -> 20.9s, 39 checks, stable over repeated runs.

tests/_fixtures.py collects the staging both this suite and test_scenarios need
-- scratch copy, seeded from a golden .i64 nothing writes back to -- which was
private to test_scenarios. Worth saying plainly: on targets/echo the seeding is
worth 0.19s, not the analysis time I assumed when I went looking. It is shared
for the deduplication and for whatever gets pointed at a bigger binary.

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/run.py b/tests/run.py
index ca0a319..4920e54 100755
--- a/tests/run.py
+++ b/tests/run.py
@@ -20,6 +20,14 @@ first time someone adds a test, **each test file declares it**::
 modules run their suite at import time). A test file with no marker is a hard
 error, so a new test can't quietly join the fast set and start needing IDA.
 
+Deliberately **serial**. Running the IDA suites concurrently looks like the
+obvious win (they are independent processes with their own worker and temp dir,
+on a 12-core box) and it is measurably a loss: 4 at a time took the suite from
+153s to 296s and killed three of them with broken-pipe worker failures --
+thumb_ui alone went 10.4s to 287.8s. idalib contends hard enough that the extra
+processes only starve each other, and a starved worker gets reaped mid-analysis,
+which reads as a flaky test rather than as load. Don't re-add --jobs.
+
 Usage::
 
     python3 tests/run.py              # everything