One more error from Yosys

I get an error from Yosys:

FOOBAR.sv:68: ERROR: syntax error, unexpected '@'

On this line:

assert__foobar_chisel3_builtin: assert property (@(posedge clock) 1'h1) else $error("Assertion failed\n at Foobar.scala:604 assert(\n"); // Foobar.scala:604:13, Mux.scala:81:61

Using:

    new circt.stage.ChiselStage()
      .execute(
        remainingArgs,
        Seq(
          ChiselGeneratorAnnotation(provider),
          circt.stage.CIRCTTargetAnnotation(circt.stage.CIRCTTarget.Verilog),
          circt.stage.CIRCTHandover(circt.stage.CIRCTHandover.CHIRRTL),
          circt.stage.FirtoolOption("--lowering-options=disallowLocalVariables,disallowPackedArrays"),
          circt.stage.FirtoolOption("--remove-unused-ports"),
          circt.stage.FirtoolOption("--disable-name-preservation"),
          circt.stage.FirtoolOption("--split-verilog"),
          circt.stage.FirtoolOption("--dedup"),
          circt.stage.FirtoolOption("-o=" + targetFolder)
        )
      )