[NTG-context] Undefined control sequence with latest beta

Hello, When running `context test.cld' on this file: --8<---------------cut here---------------start------------->8--- io.output"my-env.tex" io.write"\\startenvironment my-env\n\\def\\myTest{bla}\n\\stopenvironment\n" context.environment{"my-env"} context.starttext() context.myTest() context.stoptext() --8<---------------cut here---------------end--------------->8--- I get an `undefined control sequence' error for \myTest. How could I solve this problem please? TIA for any help, -- Peter