"Waiting on threads to park on joinable thread list timed out" with Drone.io CI

**Bug description**
I created a Drone.io pipeline with your images. I took inspiration from the gitlab and Travis examples. Here is the `.drone.yml`:

.drone.yml

```yaml
globals:
- &unity3d-base
volumes:
- name: unity3d-cache
path: /drone/src/Library

kind: pipeline
type: docker
name: 🔨 build & 🔍 test

environment:
BUILD_NAME: ${DRONE_REPO_NAME}

platform:
arch: amd64

steps:
# Build Android package with IL2CPP backend
- name: 🔨 build | 🤖 android
image: unityci/editor:2020.2.0f1-android-0.11
<<: *unity3d-base
environment:
BUILD_TARGET: Android
BUILD_APP_BUNDLE: 'false'
SCRIPTING_BACKEND: IL2CPP
UNITY_LICENSE:
from_secret: UNITY_LICENSE
commands:
- chmod +x ./ci/before_script.sh && ./ci/before_script.sh
- chmod +x ./ci/build.sh && ./ci/build.sh
when:
ref:
include:
- refs/heads/*
exclude:
- refs/heads/master
- refs/pull/*/head

# Build iOS package
- name: 🔨 build | 🍏 iOS
image: unityci/editor:2020.2.0f1-ios-0.11
<<: *unity3d-base
environment:
BUILD_TARGET: iOS
UNITY_LICENSE:
from_secret: UNITY_LICENSE
commands:
- chmod +x ./ci/build.sh && ./ci/build.sh
when:
ref:
include:
- refs/heads/*
exclude:
- refs/heads/master
- refs/pull/*/head

- name: 🔍 tests
image: unityci/editor:2020.2.0f1-windows-mono-0.11
<<: *unity3d-base
environment:
UNITY_LICENSE:
from_secret: UNITY_LICENSE
commands:
- chmod +x ./ci/test.sh && ./ci/test.sh

volumes:
- name: unity3d-cache
temp: {}
```

Im not really sure if this qualifies as a bug, because i am trying to run the images with a Drone.io CI and you don't officially support that, but...it kind of is a [mono bug](https://github.com/mono/mono/pull/5964). At least that was what i found when searching for `Waiting on threads to park on joinable thread list timed out.`, so i hope you can help me out here. And when all goes well, i would like to add the Drone config/instructions to your documentation.

**How to reproduce**
Setup Drone.io with docker and run the above pipeline config with a Unity project.

**Expected behavior**
Pipeline finishes or at least does not hang with
```
Waiting on threads to park on joinable thread list timed out.
debugger-agent: Unable to listen on 27
```

**Additional details**
The last part of the pipeline logs

Logfile

```log
...
:: Done with build
Timeout after 300 seconds while waiting async operations to finish. executeMethod 'BuildCommand.PerformBuild'

Aborting batchmode due to failure:
Timeout after 300 seconds while waiting async operations to finish. executeMethod 'BuildCommand.PerformBuild'

[Performance] Application.InitializeProject : 1 samples, Peak. 228 s (1.0x), Avg. 228 s, Total. 227.6 s (11.3%)
[Performance] Application.PackageManager.StartServer : 1 samples, Peak. 2.95 ms (1.0x), Avg. 2.95 ms, Total. 2.953 ms (0.0%)
[Performance] Application.AcquireProjectLock : 1 samples, Peak. 1.82 ms (1.0x), Avg. 1.82 ms, Total. 1.824 ms (0.0%)
[Performance] Application.InitializeEngineNoGraphics : 1 samples, Peak. 275 ms (1.0x), Avg. 275 ms, Total. 275.0 ms (0.0%)
[Performance] Application.PackageManager.Initialize : 1 samples, Peak. 2.58 s (1.0x), Avg. 2.58 s, Total. 2.579 s (0.1%)
[Performance] CurlRequestCheck : 48 samples, Peak. 99.4 us (3.2x), Avg. 31.4 us, Total. 1.506 ms (0.0%)
[Performance] PackageManager::RunRequestSynchronously : 1227 samples, Peak. 1.14 ms (80.9x), Avg. 14.1 us, Total. 17.26 ms (0.0%)
[Performance] Application.EngineGraphics.Initialize : 1 samples, Peak. 124 ms (1.0x), Avg. 124 ms, Total. 124.4 ms (0.0%)
[Performance] Application.GI.Initialize : 1 samples, Peak. 4.86 ms (1.0x), Avg. 4.86 ms, Total. 4.858 ms (0.0%)
[Performance] Application.LoadAllDefaultResourcesFromEditor : 1 samples, Peak. 4.40 ms (1.0x), Avg. 4.40 ms, Total. 4.404 ms (0.0%)
[Performance] Application.LoadMonoAssemblies : 1 samples, Peak. 9.17 s (1.0x), Avg. 9.17 s, Total. 9.170 s (0.5%)
[Performance] RestoreManagedReferences : 2 samples, Peak. 203 ms (2.0x), Avg. 101 ms, Total. 202.6 ms (0.0%)
[Performance] ProcessService.EditorAfterLoadAllAssemblies : 2 samples, Peak. 147 ms (1.2x), Avg. 119 ms, Total. 238.4 ms (0.0%)
[Performance] Application.ReadLicenseInfo : 1 samples, Peak. 40.4 ms (1.0x), Avg. 40.4 ms, Total. 40.36 ms (0.0%)
[Performance] Application.InitialScriptRefresh : 1 samples, Peak. 87.7 s (1.0x), Avg. 87.7 s, Total. 87.66 s (4.3%)
[Performance] PresetManagerPostProcessor.OnPreprocessAsset : 4511 samples, Peak. 5.47 ms (152.3x), Avg. 35.9 us, Total. 162.1 ms (0.0%)
[Performance] CancelSplashScreenOnAssetChange.OnPreprocessAsset : 4511 samples, Peak. 2.96 ms (328.6x), Avg. 8.99 us, Total. 40.56 ms (0.0%)
[Performance] Compiling Scripts : 1 samples, Peak. 64.8 s (1.0x), Avg. 64.8 s, Total. 64.82 s (3.2%)
[Performance] Package.AsyncRequest : 2 samples, Peak. 22.9 us (1.2x), Avg. 19.2 us, Total. 38.37 us (0.0%)
[Performance] AssetDatabase.ImportAssets : 8 samples, Peak. 334 ms (8.0x), Avg. 41.7 ms, Total. 333.6 ms (0.0%)
[Performance] AssetCallbacks.OnPostprocessAllAssets : 4 samples, Peak. 117 ms (4.0x), Avg. 29.2 ms, Total. 116.8 ms (0.0%)
[Performance] TMPro_TexturePostProcessor.OnPostprocessAllAssets : 4 samples, Peak. 47.6 ms (2.6x), Avg. 18.4 ms, Total. 73.43 ms (0.0%)
[Performance] SimulatedAREnvironmentImport.OnPostprocessAllAssets : 4 samples, Peak. 136 ms (3.0x), Avg. 46.1 ms, Total. 184.5 ms (0.0%)
[Performance] RetainedMode.OnPostprocessAllAssets : 4 samples, Peak. 92.5 ms (3.4x), Avg. 27.6 ms, Total. 110.2 ms (0.0%)
[Performance] EditorAtlasMonitorInjector.OnPostprocessAllAssets : 4 samples, Peak. 2.21 ms (2.6x), Avg. 848 us, Total. 3.392 ms (0.0%)
[Performance] AudioMixerPostprocessor.OnPostprocessAllAssets : 4 samples, Peak. 977 us (3.8x), Avg. 255 us, Total. 1.021 ms (0.0%)
[Performance] AssetEvents.OnPostprocessAllAssets : 8 samples, Peak. 621 us (6.0x), Avg. 103 us, Total. 824.7 us (0.0%)
[Performance] ModelImporterPostProcessor.OnPostprocessAllAssets : 4 samples, Peak. 609 ms (2.0x), Avg. 300 ms, Total. 1.200 s (0.1%)
[Performance] StyleCatalogPostProcessor.OnPostprocessAllAssets : 4 samples, Peak. 408 ms (2.6x), Avg. 159 ms, Total. 636.1 ms (0.0%)
[Performance] BuildCatalog : 2 samples, Peak. 405 ms (1.3x), Avg. 315 ms, Total. 630.3 ms (0.0%)
[Performance] Application.AssetDatabase.Refresh : 1 samples, Peak. 60.7 s (1.0x), Avg. 60.7 s, Total. 60.67 s (3.0%)
[Performance] AssetDatabase.Refresh : 1 samples, Peak. 60.7 s (1.0x), Avg. 60.7 s, Total. 60.67 s (3.0%)
[Performance] TextureImporter.Import : 469 samples, Peak. 2.14 s (21.9x), Avg. 97.9 ms, Total. 45.90 s (2.3%)
[Performance] EditorAtlasMonitorInjector.OnPostprocessTexture : 467 samples, Peak. 560 us (29.6x), Avg. 18.9 us, Total. 8.843 ms (0.0%)
[Performance] ShaderImporter.Import : 26 samples, Peak. 2.69 s (14.7x), Avg. 182 ms, Total. 4.739 s (0.2%)
[Performance] ModelImporter.Import : 2 samples, Peak. 353 ms (1.4x), Avg. 254 ms, Total. 507.6 ms (0.0%)
[Performance] FBXMaterialDescriptionPreprocessor.OnPreprocessMaterialDescription : 1 samples, Peak. 10.9 ms (1.0x), Avg. 10.9 ms, Total. 10.92 ms (0.0%)
[Performance] SketchupMaterialDescriptionPreprocessor.OnPreprocessMaterialDescription : 1 samples, Peak. 307 us (1.0x), Avg. 307 us, Total. 306.9 us (0.0%)
[Performance] ThreeDSMaterialDescriptionPreprocessor.OnPreprocessMaterialDescription : 1 samples, Peak. 219 us (1.0x), Avg. 219 us, Total. 219.1 us (0.0%)
[Performance] TreeAOImporter.OnPostprocessModel : 2 samples, Peak. 2.99 ms (2.0x), Avg. 1.52 ms, Total. 3.033 ms (0.0%)
[Performance] SceneDataContainer.TransformHierarchyChangedSetParentCallback : 3 samples, Peak. 93.2 us (2.5x), Avg. 36.6 us, Total. 109.8 us (0.0%)
[Performance] SceneVisibilityState.IsFlagSetInParents : 3 samples, Peak. 25.3 us (1.9x), Avg. 13.4 us, Total. 40.23 us (0.0%)
[Performance] Application.ImportAssetsWithMismatchingAssetImporterVersion : 1 samples, Peak. 529 ms (1.0x), Avg. 529 ms, Total. 528.7 ms (0.0%)
[Performance] Application.SyncCurrentColorSpace : 1 samples, Peak. 24.9 ms (1.0x), Avg. 24.9 ms, Total. 24.92 ms (0.0%)
[Performance] Application.OnUsbDevicesChanged : 1 samples, Peak. 35.5 us (1.0x), Avg. 35.5 us, Total. 35.48 us (0.0%)
[Performance] Application.AssetDatabase.SaveAssets : 1 samples, Peak. 10.7 ms (1.0x), Avg. 10.7 ms, Total. 10.68 ms (0.0%)
[Performance] Application.AssetInstanceCacheUpdate : 1 samples, Peak. 914 ns (1.0x), Avg. 914 ns, Total. 914.0 ns (0.0%)
[Performance] Application.UnityExtensions.Initialize : 1 samples, Peak. 4.37 ms (1.0x), Avg. 4.37 ms, Total. 4.369 ms (0.0%)
[Performance] Application.InitializeManagedCompilationPipeline : 1 samples, Peak. 209 ms (1.0x), Avg. 209 ms, Total. 209.1 ms (0.0%)
[Performance] Application.ExecuteStartups : 1 samples, Peak. 503 ms (1.0x), Avg. 503 ms, Total. 503.4 ms (0.0%)
[Performance] Application.InitializeMenu : 1 samples, Peak. 143 ms (1.0x), Avg. 143 ms, Total. 142.5 ms (0.0%)
[Performance] UpdateAllMenus : 1 samples, Peak. 143 ms (1.0x), Avg. 143 ms, Total. 142.5 ms (0.0%)
[Performance] Application.editorInitializingProject : 1 samples, Peak. 167 us (1.0x), Avg. 167 us, Total. 167.4 us (0.0%)
[Performance] GUIView.RepaintAll.PlayerLoopController : 4 samples, Peak. 14.2 us (1.9x), Avg. 7.37 us, Total. 29.48 us (0.0%)
[Performance] Application.InvokeFinishedLoadingProject : 1 samples, Peak. 102 ms (1.0x), Avg. 102 ms, Total. 101.7 ms (0.0%)
[Performance] ProcessService.OnProjectLoaded : 1 samples, Peak. 84.6 ms (1.0x), Avg. 84.6 ms, Total. 84.64 ms (0.0%)
[Performance] GenerateAssemblyTypeInfos : 2 samples, Peak. 2.72 s (1.0x), Avg. 2.61 s, Total. 5.225 s (0.3%)
[Performance] Inspector.InitOrRebuild : 2 samples, Peak. 4.36 ms (1.4x), Avg. 3.08 ms, Total. 6.156 ms (0.0%)
Start importing ProjectSettings/ProjectSettings.asset using Guid(00000000000000004000000000000000) Importer(-1,00000000000000000000000000000000) -> (artifact id: '9ef8fd4c7a59f7cf43aa1496d08415bc') in 0.019765 seconds
Refreshing native plugins compatible for Editor in 4.70 ms, found 28 plugins.
Preloading 0 native plugins for Editor in 0.00 ms.
RefreshInfo: StopAssetImportingV2(NoUpdateAssetOptions) scanfilter:
RefreshProfiler: Total: 998.206ms
InvokeBeforeRefreshCallbacks: 0.004ms
ApplyChangesToAssetFolders: 0.383ms
Scan: 41.565ms
OnSourceAssetsModified: 0.726ms
InitializeImportedAssetsSnapshot: 102.928ms
GetAllGuidsForCategorization: 1.235ms
CategorizeAssets: 41.797ms
ImportAndPostprocessOutOfDateAssets: 757.511ms (6.092ms without children)
ImportManagerImport: 26.141ms (3.029ms without children)
ImportInProcess: 22.774ms
UpdateCategorizedAssets: 0.337ms
PostProcessAllAssets: 686.529ms
ReloadImportedAssets: 0.003ms
EnsureUptoDateAssetsAreRegisteredWithGuidPM: 1.073ms
InitializingProgressBar: 0.014ms
PostProcessAllAssetNotificationsAddChangedAssets: 0.755ms
OnDemandSchedulerStart: 17.900ms
RestoreLoadedAssetsState: 3.414ms
UpdateImportedAssetsSnapshot: 15.590ms
ReloadSourceAssets: 3.223ms
UnloadImportedAssets: 0.431ms
Hotreload: 6.381ms
FixTempGuids: 0.020ms
GatherAllCurrentPrimaryArtifactRevisions: 1.553ms
UnloadStreamsBegin: 0.613ms
LoadedImportedAssetsSnapshotReleaseGCHandles: 2.042ms
GetLoadedSourceAssetsSnapshot: 9.024ms
PersistCurrentRevisions: 0.521ms
UnloadStreamsEnd: 2.377ms
Untracked: 25.872ms
AcceleratorClientConnectionCallback - disconnected - :0
Cleanup mono
latform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/TempStubs.cpp:PlatformImageForIconForExtension
./Editor/Platform/Linux/UsbDevices.cpp:UsbDevicesQuery
Waiting on threads to park on joinable thread list timed out.
debugger-agent: Unable to listen on 27
```