There is a nebulously named host_debug_impeller_vulkan configuration for Engine CI:

"gn": [
    "--runtime-mode",
    "debug",
    "--unoptimized",
    "--prebuilt-dart-sdk",
    "--target-dir",
    "host_debug_impeller_vulkan"
 ],
"name": "host_debug_impeller_vulkan",

It appears to have been added in flutter/engine@40019b7, and used to contain additional flags, such as "--enable-impeller-vulkan" and "--engine-capture-core-dump", which are no longer used in today's configuration (IIRC --enable-impeller-vulkan is enabled by default outside of iOS/MacOS hosts?)

@zanderso also mentioned on chat:

The other host_debug_unopt build builds to run with asan and lsan: https://github.com/flutter/engine/blob/main/ci/builders/linux_unopt.json#L14. My guess is that when the tests under host_debug_impeller_vulkan were added, they required some other different flags that have since been removed, or that they didn't pass under asan and lsan.

We should really be running our Impeller/Vulkan tests with ASAN/LSAN, and have 1 less configuration.