Hitting Classic PDB format is not supported on CoreCLR. while using 6.0 version of the ILASM package

[Anipik]

Darc updated the ilasm package version to 6.0 and we started hitting this

EXEC : warning : Classic PDB format is not supported on CoreCLR. [C:\git\runtime3\src\libraries\System.Runtime.CompilerServices.Unsafe\src\System.Runtime.CompilerServices.Unsafe.ilproj]

is this expected ?

@dotnet/runtime-infrastructure

[Dotnet-GitSync-Bot]

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[safern]

Maybe something changed in arcade? I saw we hit this on the arcade update, right?

[ericstj]

Hmm, I'd expect us to be using portable PDBs (as opposed to classic) everywhere now.

[ViktorHofer]

I might be wrong but could this be connected to @ericstj's change where he stopped producing the old pdb format in libraries?

[ericstj]

I changed it the other way. That warning indicates that the build is asking ILAsm to produce classic PDB which is not what we want.

[ericstj]

So here is where the ILSDK maps DebugType property to commandline args to ILAsm, perhaps that needs some work?

runtime/src/coreclr/src/.nuget/Microsoft.NET.Sdk.IL/targets/Microsoft.NET.Sdk.IL.targets

Lines 131 to 133 in b9de3d0

	<_IlasmSwitches Condition="'$(DebugType)' == 'Full'">$(_IlasmSwitches) -DEBUG</_IlasmSwitches>
	<_IlasmSwitches Condition="'$(DebugType)' == 'Impl'">$(_IlasmSwitches) -DEBUG=IMPL</_IlasmSwitches>
	<_IlasmSwitches Condition="'$(DebugType)' == 'PdbOnly'">$(_IlasmSwitches) -DEBUG=OPT</_IlasmSwitches>

[akoeplinger]

See the discussion in #45387 (comment)

[radical]

Seeing this in some builds:
https://dev.azure.com/dnceng/public/_build/results?buildId=905221&view=results (PR #45451)
https://dev.azure.com/dnceng/public/_build/results?buildId=907315&view=results (PR #45387)

[safern]

@radical PR #45451 I don't think it hit this error, it actually hit a networking issue on the Browser leg and the other is a test failure (Unless I'm missing something).

PR #45387 is the PR that is updating the version of ILASM causing this, so I'm going to remove blocking-clean-ci as this is an issue on the ILASM version that we're updating to, but not manifesting on all PRs, just the PR trying to update that version.

[jkotas]

This warning is not useful. I think we should get rid of this warning and always emit the portable PDBs.