Profiles cannot find default Java runtime when using --workDir

I moved all the contents of my %APPDATA%\.minecraft folder to the folder E:\Minecraft\minecraft-c0wg0d.

I have a shortcut to start the launcher with the following:

E:\Minecraft\minecraft-c0wg0d\MinecraftLauncher.exe --workDir . --launcherui

For all my profiles, I do NOT specify the javaw.exe location, because it is in the default location, which is .\runtime\jre-x64\bin\javaw.exe.  If I try to launch Minecraft, I get the following error:

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Unable to locate the Java runtime.
Error details: The operation completed successfully.

Filename on disk:
Path: .
Exists: Directory

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If I manually specify the javaw.exe file, it works fine.  I have dozens of profiles and I don't want to have to specify the Java runtime location for all of them, and I don't understand why it can't find it in the current workDir directory.  This seems like a bug to me.