Add config switch to fully disable hot-reload

[jkotas]

Enabling metadata updater used by hot-reload causes the runtime and libraries to take codepaths conditionalized by MetadataUpdater.IsSupported property. These codepaths receive less thorough testing and have higher risk of containing bugs. #78218 has been an example of such bug.

Metadata updater is automatically enabled when managed debugger is attached and there is no way to suppress it:

runtime/src/coreclr/vm/assemblynative.cpp

Line 1365 in 3dbc850

result = CORDebuggerAttached() || g_pConfig->ForceEnc() || g_pConfig->DebugAssembliesModifiable();

. It means that a bug in hot-reload specific codepath can make the application impossible to debug. This situation was encountered in #78218.

We should add a config switch that unconditionally disables metadata updater and that can be used as a workaround for bugs in hot-reload specific codepaths.

Context: #78218 (comment)

Tagging subscribers to this area: @tommcdon
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Enabling metadata updater used by hot-reload causes the runtime and libraries to take codepaths conditionalized by MetadataUpdater.IsSupported property. These codepaths receive less thorough testing and have higher risk of containing bugs. #78218 has been an example of such bug.

Metadata updater is automatically enabled when managed debugger is attached and there is no way to suppress it:

runtime/src/coreclr/vm/assemblynative.cpp

Line 1365 in 3dbc850

result = CORDebuggerAttached() || g_pConfig->ForceEnc() || g_pConfig->DebugAssembliesModifiable();

. It means that a bug in hot-reload specific codepath can make the application impossible to debug. This situation was encountered in #78218.

We should add a config switch that unconditionally disables metadata updater and that can be used as a workaround for bugs in hot-reload specific codepaths.

Context: #78218 (comment)

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

[jkotas]

cc @jogibear9988

[marek-safar]

/cc @lambdageek