Detect when evaluated by JETLS

[EdsterG]

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• I have searched existing issues and confirmed this is not a duplicate.

Description

I'ld like to write code that looks like this:

macro add_definition(fn)
    def = ExprTools.splitdef(fn)
    name = def[:name]
    if isdefined(MyMacros, name) && !IS_JETLS_LOADED[])
        # Forbid overwriting macros when not evaluated by JETLS.
        error(name, " macro already defined, cannot redefine")
    end
    ...
end

For Revise I can do something like this:

IS_REVISE_LOADED::ScopedValue{Bool} = ScopedValue(false)

function __init__()
    if haskey(Base.loaded_modules,
              Base.PkgId(Base.UUID("295af30f-e4ad-537b-8983-00126c2a3abe"), "Revise"))
        global IS_REVISE_LOADED = ScopedValue(true)
    end
end

but this pattern doesn't seem to work for JETLS.

Is there any way to identify from within a macro whether or not it's currently being evaluated by JETLS?

Additional context (optional)

No response