Support sourcemap data pass-through for imported CSS files

I have tried many differents options to import a css file with sourcemaps reference included into my less file but I always loose the sourcemaps.

Less is correctly generating the sourcemaps from css file to less compiled file.

My case :
I am generating somme css files with less (let's call it fileA.less [importing fileA1.less, fileA2.less] which compile to fileA.css and fileA.cass.map)
In another less file in another project I am importing fileA in my fileB :

/*fileB.less content*/
@import "/path/to/my/fileA.css"

fileB.less compile to fileB.css and fileB.css.map but this map only reference fileA.css not the fileA1 and fileA2 import.

I have tried diffrent imports styles but I only get correct sourcemaps when recompiling fileA i.e. importing fileA.less in fileB.less

It would be really helfull if this information wasn't lost..

Start by tracing how Less handles an imported CSS file and how it emits the resulting source map. Verify the behavior with a case where fileA.css references fileA1.less and fileA2.less, then consider the work complete when fileB.css.map preserves those original sources instead of only referencing fileA.css.