DOTNET_ vs COMPlus_ env var prefix for creating dumps

[ManickaP]

Based on this docs: https://docs.microsoft.com/en-us/dotnet/core/diagnostics/dumps the environment variable DOTNET_DbgEnableMiniDump should work the same way as COMPlus_DbgEnableMiniDump.
However, the former (DOTNET_...) didn't work for me and the latter (COMPlus_) did. Is the documentation wrong or is this a bug/missing feature?

Running in mcr.microsoft.com/dotnet/nightly/sdk:6.0-bullseye-slim docker image:

.NET SDK (reflecting any global.json):
 Version:   6.0.100-rc.1.21457.2
 Commit:    1aefb20570

Runtime Environment:
 OS Name:     debian
 OS Version:  11
 OS Platform: Linux
 RID:         debian.11-x64
 Base Path:   /usr/share/dotnet/sdk/6.0.100-rc.1.21457.2/

Host (useful for support):
  Version: 6.0.0-rc.1.21451.13
  Commit:  d7619cd4b1

.NET SDKs installed:
  6.0.100-rc.1.21457.2 [/usr/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.0-rc.1.21452.15 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.0-rc.1.21451.13 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

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Issue Details

---

Based on this docs: https://docs.microsoft.com/en-us/dotnet/core/diagnostics/dumps the environment variable DOTNET_DbgEnableMiniDump should work the same way as COMPlus_DbgEnableMiniDump.
However, the former (DOTNET_...) didn't work for me and the latter (COMPlus_) did. Is the documentation wrong or is this a bug/missing feature?

Running in mcr.microsoft.com/dotnet/nightly/sdk:6.0-bullseye-slim docker image:

.NET SDK (reflecting any global.json):
 Version:   6.0.100-rc.1.21457.2
 Commit:    1aefb20570

Runtime Environment:
 OS Name:     debian
 OS Version:  11
 OS Platform: Linux
 RID:         debian.11-x64
 Base Path:   /usr/share/dotnet/sdk/6.0.100-rc.1.21457.2/

Host (useful for support):
  Version: 6.0.0-rc.1.21451.13
  Commit:  d7619cd4b1

.NET SDKs installed:
  6.0.100-rc.1.21457.2 [/usr/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.0-rc.1.21452.15 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.0-rc.1.21451.13 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Author:	ManickaP
Assignees:	-
Labels:	area-Diagnostics-coreclr, untriaged
Milestone:	-

[hoyosjs]

This should've started working with #50507, not sure why it didn't. Regardless we should amend the public docs to at least state this is only a 6.0+ feature.

[hoyosjs]

Turns our this is handled in the procabort handler which is in the PAL. Such layer doesn't have the CLR's config facility, so we do a hard manual check:

runtime/src/coreclr/pal/src/thread/process.cpp

Lines 3278 to 3297 in 331823f

	PROCAbortInitialize()
	{
	char* enabled = getenv("COMPlus_DbgEnableMiniDump");
	if (enabled != nullptr && _stricmp(enabled, "1") == 0)
	{
	char* dumpName = getenv("COMPlus_DbgMiniDumpName");
	char* dumpType = getenv("COMPlus_DbgMiniDumpType");
	char* diagStr = getenv("COMPlus_CreateDumpDiagnostics");
	BOOL diag = diagStr != nullptr && strcmp(diagStr, "1") == 0;
	char* crashReportStr = getenv("COMPlus_EnableCrashReport");
	BOOL crashReport = crashReportStr != nullptr && strcmp(crashReportStr, "1") == 0;
	char* program = nullptr;
	char* pidarg = nullptr;
	if (!PROCBuildCreateDumpCommandLine(g_argvCreateDump, &program, &pidarg, dumpName, dumpType, diag, crashReport))
	{
	return FALSE;
	}
	}
	return TRUE;

Affected variables:

• COMPlus_EnableAlternateStackCheck
• COMPlus_EnableAssertDialog
• COMPlus_DefaultStackSize
• COMPlus_UseDefaultBaseAddr
• COMPlus_CodeHeapReserveForJumpStubs (
• COMPlus_LTTng
• COMPlus_DbgEnableMiniDump
• COMPlus_DbgMiniDumpName
• COMPlus_DbgMiniDumpType
• COMPlus_CreateDumpDiagnostics
• COMPlus_EnableCrashReport

cc: @AaronRobinsonMSFT

[AaronRobinsonMSFT]

Regardless we should amend the public docs to at least state this is only a 6.0+ feature.

That is documented. Unfortunately it seems some of the official variables do their own thing – this is unfortunate. This isn't a .NET 6 issue really so we can move this to .NET 7 for now.