Device tree debugging

I have a very basic question about the Linux Device TreI'm trying to build a device tree coming from an existing project, the device tree compiler just refuses like this:

Error: fsl-imx8mq-var-dart-common.dtsi:722.18-19 syntax errorFATAL ERROR: Unable to parse input tree

It's quite clear that I'm stumbling into some kind of syntax error, but I'm puzzled by the numbers reported, i expected 722 to be the line number, but it seems not the case.

What is the meaning of those number? I could not find a way to make dtc more verbose.

(I'm not adding the device tree yet since it's 2000 lines)

Thanks in advance