Fix rtloader windows tests on Bazel

[alopezz]

What does this PR do?

It uses a copy of the "Python Home" for rtloader on windows instead of picking it from external repo targets. This fixes the failing rtloader tests and so the PR also reenables them.

Motivation

#incident-54552

These tests seem to have been broken ever since we enabled runfiles on Windows in #48206. From what it looks like, these tests were being systematically cached on a passing result, which hid the issue for a long time. These tests have recently started to actually run and fail (which caused the incident).

In fact, the first attempt at reenabling the runfiles was reverted, the errors being essentially the same that we're seeing now (https://gitlab.ddbuild.io/DataDog/datadog-agent/-/jobs/1529936875), which makes it clearer that enabling runfiles is what breaks this test.

Describe how you validated your changes

Passing CI (on an uncached run): https://gitlab.ddbuild.io/DataDog/datadog-agent/-/jobs/1683378542#L4078

Additional Notes

In the original code, Rlocation with runfiles enabled pointed to a path that didn't really exist or was unreachable. I'm still trying to fully figure out why this happens.

• Enabling runfiles changing from creating just the manifest vs populating the runfiles forder with symlinks (source).
• For external repositories, a symlink (actually a junction in windows) is created to each external repository directory (source), from <output_base>/execroot/<main repo name>/external/<external repo name> to <output_base>/external/<external repo name>.
• When runfiles are disabled, RUNFILES_MANIFEST_FILE is set and the runfiles package reads from the manifest, and otherwise looks at the runfiles directory (RUNFILES_DIR) directly (source).

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor a0e32982:

Results for datadog-agent_7.80.0~devel.git.793.2c07e7e.pipeline.113203509-1_amd64.deb:

No change detected

[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor a0e3298
📊 Static Quality Gates Dashboard
🔗 SQG Job

33 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64	743.419 MiB
✅	agent_deb_amd64_fips	701.462 MiB
✅	agent_heroku_amd64	309.671 MiB
✅	agent_msi	608.722 MiB
✅	agent_rpm_amd64	743.402 MiB
✅	agent_rpm_amd64_fips	701.446 MiB
✅	agent_rpm_arm64	721.153 MiB
✅	agent_rpm_arm64_fips	682.311 MiB
✅	agent_suse_amd64	743.402 MiB
✅	agent_suse_amd64_fips	701.446 MiB
✅	agent_suse_arm64	721.153 MiB
✅	agent_suse_arm64_fips	682.311 MiB
✅	docker_agent_amd64	803.576 MiB
✅	docker_agent_arm64	806.128 MiB
✅	docker_agent_jmx_amd64	994.496 MiB
✅	docker_agent_jmx_arm64	985.827 MiB
✅	docker_cluster_agent_amd64	206.822 MiB
✅	docker_cluster_agent_arm64	220.826 MiB
✅	docker_cws_instrumentation_amd64	7.154 MiB
✅	docker_cws_instrumentation_arm64	6.689 MiB
✅	docker_dogstatsd_amd64	39.499 MiB
✅	docker_dogstatsd_arm64	37.690 MiB
✅	docker_host_profiler_amd64	302.240 MiB
✅	docker_host_profiler_arm64	313.759 MiB
✅	dogstatsd_deb_amd64	30.155 MiB
✅	dogstatsd_deb_arm64	28.280 MiB
✅	dogstatsd_rpm_amd64	30.155 MiB
✅	dogstatsd_suse_amd64	30.155 MiB
✅	iot_agent_deb_amd64	44.365 MiB
✅	iot_agent_deb_arm64	41.338 MiB
✅	iot_agent_deb_armhf	42.043 MiB
✅	iot_agent_rpm_amd64	44.366 MiB
✅	iot_agent_suse_amd64	44.366 MiB

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: f27b2874-2779-41b7-a4ca-e525b182dd9b

Baseline: bdca523
Comparison: 10b2603
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_cpu	% cpu utilization	-1.86	[-4.77, +1.04]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	tcp_syslog_to_blackhole	ingress throughput	+1.28	[+1.11, +1.46]	1	Logs
➖	ddot_metrics	memory utilization	+0.26	[+0.06, +0.47]	1	Logs
➖	otlp_ingest_logs	memory utilization	+0.20	[+0.09, +0.31]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	+0.03	[-0.12, +0.18]	1	Logs
➖	uds_dogstatsd_to_api_v3	ingress throughput	+0.02	[-0.18, +0.21]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	+0.01	[-0.19, +0.21]	1	Logs
➖	file_tree	memory utilization	+0.00	[-0.04, +0.05]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.00	[-0.09, +0.09]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.02	[-0.45, +0.41]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	-0.03	[-0.54, +0.47]	1	Logs
➖	ddot_metrics_sum_cumulativetodelta_exporter	memory utilization	-0.06	[-0.30, +0.18]	1	Logs
➖	docker_containers_memory	memory utilization	-0.07	[-0.17, +0.02]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.08	[-0.47, +0.31]	1	Logs
➖	uds_dogstatsd_20mb_12k_contexts_20_senders	memory utilization	-0.08	[-0.13, -0.04]	1	Logs
➖	otlp_ingest_metrics	memory utilization	-0.17	[-0.33, -0.01]	1	Logs
➖	ddot_metrics_sum_delta	memory utilization	-0.20	[-0.39, -0.02]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-0.20	[-0.24, -0.17]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.20	[-1.19, +0.78]	1	Logs bounds checks dashboard
➖	quality_gate_idle	memory utilization	-0.29	[-0.34, -0.25]	1	Logs bounds checks dashboard
➖	ddot_metrics_sum_cumulative	memory utilization	-0.53	[-0.68, -0.38]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	-0.69	[-0.93, -0.44]	1	Logs bounds checks dashboard
➖	ddot_logs	memory utilization	-0.86	[-0.93, -0.79]	1	Logs
➖	docker_containers_cpu	% cpu utilization	-1.86	[-4.77, +1.04]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	docker_containers_cpu	simple_check_run	10/10	699 ≥ 26
✅	docker_containers_memory	memory_usage	10/10	244.82MiB ≤ 370MiB
✅	docker_containers_memory	simple_check_run	10/10	713 ≥ 26
✅	file_to_blackhole_0ms_latency	memory_usage	10/10	0.16GiB ≤ 1.20GiB
✅	file_to_blackhole_0ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10	0.20GiB ≤ 1.20GiB
✅	file_to_blackhole_1000ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_100ms_latency	memory_usage	10/10	0.17GiB ≤ 1.20GiB
✅	file_to_blackhole_100ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_500ms_latency	memory_usage	10/10	0.18GiB ≤ 1.20GiB
✅	file_to_blackhole_500ms_latency	missed_bytes	10/10	0B = 0B
✅	quality_gate_idle	intake_connections	10/10	3 ≤ 4	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	143.38MiB ≤ 147MiB	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	3 ≤ 4	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	471.14MiB ≤ 495MiB	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	3 ≤ 6	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	175.27MiB ≤ 195MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	345.54 ≤ 2000	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	3 ≤ 6	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	371.72MiB ≤ 430MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.

[jeremy-hanna]

👍 for agent-runtime owned files

[nathan-b]

Very solid

[alopezz]

/merge

[gh-worker-devflow-routing-ef8351]

View all feedbacks in Devflow UI.

2026-05-15 07:48:31 UTC ℹ️ Start processing command /merge

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2026-05-15 07:48:36 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 3h (p90).

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2026-05-15 08:55:49 UTC ℹ️ MergeQueue: This merge request was merged