testing/igt: Add troubleshooting due to version mismatch.
BUG=b:181033521,b:186556348
TEST=N/A
Change-Id: If93142044b39fcc1036c17a39b1115f3690d1649
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/docs/+/2893730
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Mark Yacoub <markyacoub@google.com>
Commit-Queue: Mark Yacoub <markyacoub@google.com>
diff --git a/testing/igt.md b/testing/igt.md
index 31bd82d..0313c48 100644
--- a/testing/igt.md
+++ b/testing/igt.md
@@ -163,7 +163,20 @@
```
Make sure you have the right [ProxyCommand](https://g3doc.corp.google.com/company/teams/cloudtop/faq.md?cl=head#ssh) in place and this [workaround](https://groups.google.com/a/google.com/g/chromeos-chatty-eng/c/opC-HyMTe8E/m/UkIi7diBCAAJ) to enable skylab from chroot.
-5. ### If the test isn't starting on the DUT
- Make sure the UI is stopped on your DUT by doing `(device)$ stop ui`
+5. ### If the test isn't starting on the DUT: `Can't become DRM master`
+if you see this error on your DUT
+```
+Test requirement: __igt_device_set_master(fd) == 0
+Can't become DRM master, please check if no other DRM client is running.
+```
+Make sure the UI is stopped on your DUT by doing `(device)$ stop ui`
+
+6. ### If the test isn't starting on the DUT: `version not found`
+if your error looks like
+```
+./kms_dp_aux_dev: /lib64/libc.so.6: version `GLIBC_2.30' not found (required by /usr/local/lib64/libigt.so.0)
+```
+Likely due to an uprev of the libraries, resulting in a mismatch between ChromeOS and userspace.
+Getting the most recent ChromeOS image on your DUT should fix the problem.
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