Hot reload becomes very slow with dotnet watch and Blazor

[antoine-defrahan]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I'm making a Blazor app with .NET 8.0.100 and try to use the Hot Reload functionality of the dotnet watch command.

It works fine at first, then usually after a few minutes of usage it becomes increasingly slow and can take up to minutes to detect a change in the code. It looks like the time to detect a change is approximately doubled each time (see screenshot below).

Expected Behavior

Relatively fast detection of changes and browser refresh when using dotnet watch.

Steps To Reproduce

• Create a new Blazor project with dotnet new blazor
• Try to make a page with dotnet watch on Ubuntu using a terminal

Exceptions (if any)

No response

.NET Version

8.0.100

Anything else?

I tried using different browsers but the problem remained.

IDE

VS Code 1.85.0

dotnet --info output

.NET SDK:
Version: 8.0.100
Commit: 57efcf1350
Workload version: 8.0.100-manifests.6c33ef20

Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /usr/share/dotnet/sdk/8.0.100/

.NET workloads installed:
Workload version: 8.0.100-manifests.6c33ef20
There are no installed workloads to display.

Host:
Version: 8.0.0
Architecture: x64
Commit: 5535e31a71

.NET SDKs installed:
8.0.100 [/usr/share/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 7.0.11 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 7.0.11 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
None

Environment variables:
Not set

global.json file:
Not found

[antoine-defrahan]

It behaves better when I disable Auto-Save in VS Code.
It seems to delay the issue.
Almost like making too many edits too fast makes the software stuck somewhere.

Edit 12/15/23 - It doesn't seem to be much correlated after all; the behavior for Hot Reload to become stuck seems to be rather random

[mkArtakMSFT]

Thanks for contacting us. What project are you making your edits in? Can you share more details about the exact scenario where you hit this problem?

Hi @antoine-defrahan. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[KennethHoff]

I also experienced this when I was testing out Blazor SSR about a month ago. It was almost like it was recompiling every generation instead of only the newest, but that's just a hypothesis

[antoine-defrahan]

Hi @mkArtakMSFT, thanks for your reply.

I'm currently only making edits in the server folder of the project.
The pages are rendered either with Static Server or with Interactive Server modes.

It usually goes like this:

1. I execute successfully dotnet watch in a terminal to build and run the project.
2. I open the browser tab to access the app and start making changes in a Razor component
3. Hot Reload usually works fine at first and then some time after that (haven't found any pattern yet), it takes longer than usual and the time to detect changes increases (usually more or less double each time)
4. Sometimes Hot Reload comes back and executes quickly, sometimes it stays stuck and the time to detect changes keeps on increasing. Sometimes it's a mix of both

I tried not editing any C# code and making only markup edits in .razor files, but the problem remained even so.

I have to mention that someone is working with me on the same project but on a Windows machine with Visual Studio. Hot Reload seems to work fine for him. @KennethHoff are you on Linux as well ?

Is there a way to get more verbose logs for Hot Reload? I tried setting the env variable Microsoft_CodeAnalysis_EditAndContinue_LogDir as per #52596, but couldn't find anything relevant after Hot Reload became stuck:

Trace.log

Checksum differs for source file '/myHiddenPathToServerFolder/obj/Debug/net8.0/BeautifulSports.AssemblyInfo.cs'

Session #1 started.

EmitSolutionUpdate 1.1: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.1 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.2: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.2 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.3: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.3 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.4: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.4 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.5: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.5 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.6: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.6 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.7: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.7 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.8: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.8 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.9: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.9 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.10: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.10 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.11: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.11 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.12: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.12 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.13: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.13 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

EmitSolutionUpdate 1.14: '<null>'

Found 1 potentially changed document(s) in project '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Document changed, added, or deleted: 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs'

Project summary for '/myHiddenPathToServerFolder/BeautifulSports.csproj': ValidChanges

Emitting update of '/myHiddenPathToServerFolder/BeautifulSports.csproj'

Solution update 1.14 status: Ready

Module update: capabilities=[Baseline], types=[02000057,020000AC], methods=[0600024F,06000250]

Solution update diagnostics: #1 [/myHiddenPathToServerFolder/BeautifulSports.csproj: /myHiddenPathToServerFolder/Migrations/20231207154528_InitDB.cs(1,7): hidden CS8933: The using directive for 'System' appeared previously as global using, ...]

Session #1 ended.

Analysis.log

Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline
Capabilities required by 'Microsoft.NET.Sdk.Razor.SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator/Components_Pages_Dashboard_razor.g.cs': Baseline