[Bug]: can not use a local build emitter in tsp 0.67.1

[dolauli]

Describe the bug

I used to be able to use a local build emitter to generate code for testing or debugging purposes.

tsp compile ./ --emit c:\Users\<username>\source\autorest.powershell\packages\typespec-powershell

However, after upgrading to TypeSpec/Compiler 0.67.1, I found that it no longer works.

I noticed two major issues

1. It will report issues as below.

Diagnostics were reported during compilation:

../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/main.tsp:21:1 - error @azure-tools/typespec-azure-resource-manager/single-arm-provider: Only one @armProviderNamespace can be declared in a typespec spec at once.
> 21 | @armProviderNamespace
     | ^^^^^^^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/WebhookResource.tsp:29:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing-arm-namespace: The @armProviderNamespace decorator must be used to define the ARM namespace of the service.  This is best applied to the file-level namespace.
> 29 | model WebhookResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/SnapshotResource.tsp:23:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing-arm-namespace: The @armProviderNamespace decorator must be used to define the ARM namespace of the service.  This is best applied to the file-level namespace.
> 23 | model SnapshotResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ScopingConfigurationResource.tsp:31:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing-arm-namespace: The @armProviderNamespace decorator must be used to define the ARM namespace of the service.  This is best applied to the file-level namespace.
> 31 | model ScopingConfigurationResource
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/EvidenceResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing-arm-namespace: The @armProviderNamespace decorator must be used to define the ARM namespace of the service.  This is best applied to the file-level namespace.
> 25 | model EvidenceResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ReportResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing-arm-namespace: The @armProviderNamespace decorator must be used to define the ARM namespace of the service.  This is best applied to the file-level namespace.
> 25 | model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ReportResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing: No @armResource registration found for type ReportResource
> 25 | model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/WebhookResource.tsp:29:7 - error @azure-tools/typespec-azure-resource-manager/parent-type: Parent type ReportResource of WebhookResource is not registered as an ARM resource type.
> 29 | model WebhookResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ReportResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing: No @armResource registration found for type ReportResource
> 25 | model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/WebhookResource.tsp:29:7 - error @azure-tools/typespec-azure-resource-manager/parent-type: Parent type ReportResource of WebhookResource is not registered as an ARM resource type.
> 29 | model WebhookResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ReportResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing: No @armResource registration found for type ReportResource
> 25 | model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/SnapshotResource.tsp:23:7 - error @azure-tools/typespec-azure-resource-manager/parent-type: Parent type ReportResource of SnapshotResource is not registered as an ARM resource type.
> 23 | model SnapshotResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^^^
../C:/Users/xidi/source/autorest.powershell/tests-upgrade/tests-emitter/AppComplianceAutomation.Management/resources/ReportResource.tsp:25:7 - error @azure-tools/typespec-azure-resource-manager/arm-resource-missing: No @armResource registration found for type ReportResource
> 25 | model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
     |       ^^^^^^^^^^^^^^
...

2. The API listServices will return two duplicated services.

Some investigation

The root cause of the issue appears to be the presence of two copies of TypeSpec/Compiler: one in my emitter project and another in my test project.

How to workaround the issue

I can work around the issue by packaging my emitter locally and then installing the emitter package. However, this process is very inconvenient for testing and debugging my emitter.

Reproduction

1. Install node 20 and rush.
2. Clone the repo https://github.com/dolauli/autorest.powershell/tree/tspupgrade
3. Go to the root folder and execute rush update and rush rebuild
4. Go to tests-upgrade/tests-emitter, edit package.json, remove "@azure-tools/typespec-powershell": "file:../../common/temp/artifacts/packages/azure-tools-typespec-powershell-0.0.1.tgz", and run npm install
5. Install tsp compiler npm install -g @typespec/compiler@latest
6. Go to tests-upgrade/tests-emitter/AppComplianceAutomation.Management and run tsp compile ./ --emit c:\Users\<username>\source\autorest.powershell\packages\typespec-powershell or node --inspect-brk 'C:\Users\<username>\source\autorest.powershell\packages\typespec-powershell\node_modules\@typespec\compiler\cmd\tsp.js' compile ./ --emit C:\Users\<username>\source\autorest.powershell\packages\typespec-powershell to debug the code
7. You will see the issues I mention above

Following the same steps with TSP before version 0.67.1, everything worked fine. You can check out the main branch (which still uses version 0.64.0) of the repo mentioned above to give it a try.

How to workaround

1. Add "@azure-tools/typespec-powershell": "file:../../common/temp/artifacts/packages/azure-tools-typespec-powershell-0.0.1.tgz", back to the package.json file I mentioned above
2. Pack the emitter locally rush publish --publish --pack --include-all --tag latest
3. Go to tests-upgrade/tests-emitter/ and run npm install
4. Go to tests-upgrade/tests-emitter/AppComplianceAutomation.Management, and run tsp compile ./ --emit @azure-tools/typespec-powershell
5. Everything works fine

Checklist

• Follow our Code of Conduct
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.

[markcowl]

investigate to determine the issue in this sprint

[timotheeguerin]

Initial finiding this doesn't repro in a simple case of nested spec inside an emitter

> tsp compile . --emit ~/dev/test/test-nested
TypeSpec compiler v0.67.2

✔ Compiling
✔ test-nested    tsp-output/test-nested/

Compilation completed successfully.

[timotheeguerin]

Ok so the issue is that there is multiple instances of libraries getting loaded in those cases

warning incompatible-library: Multiple versions of "@azure-tools/typespec-client-generator-core" library were loaded:
  - Version: "0.53.0" installed at "/Users/timotheeguerin/dev/azsdk/autorest.powershell/tests-upgrade/tests-emitter/node_modules/@azure-tools/typespec-client-generator-core"
  - Version: "0.53.1" installed at "/Users/timotheeguerin/dev/azsdk/autorest.powershell/common/temp/node_modules/.pnpm/@[email protected]_@[email protected]_@t_zrbv43bb4ecg5hztsrjne4irgu/node_modules/@azure-tools/typespec-client-generator-core"

[timotheeguerin]

Ok so the problem seems to be that somehow the mutated namespace is not part of a realm which cause it to complain about the error above.

[timotheeguerin]

Ok so the problem is that Relam is treated as a singleton class and keeps track of types added to it but if you load multiple instance of it(like in this example) it will have multiple singleton and not behave as expected.