Google Closure Compiler ignores input source maps

build.sh

java \
-jar compiler.jar \
--js main.js \
--compilation_level ADVANCED_OPTIMIZATIONS \
--js_output_file main.min.js \
--create_source_map main.min.js.map \
--source_map_format V3

main.js

function main(args) {
  var i = 0;
  for (i = 0; i < args.length; i++) {
    print(args[i]);
  }
}
var list = [];
list.push("a");
list.push("b");
list.push("c");
main(list);
//# sourceMappingURL=main.js.map

main.js.map

{"version":3,"sources":["main.bit"],"sourcesContent":["import void print(string text);\n\nvoid main(List<string> args) {\n  int i;\n  for (i = 0; i < args.length; i++) {\n    print(args.get(i));\n  }\n}\n\nList<string> list = new List<string>();\nlist.push(\"a\");\nlist.push(\"b\");\nlist.push(\"c\");\nmain(list);\n"],"names":[],"mappings":",AAEA;AACE;AACA;AACE;;;AAIJ;AACA;AACA;AACA;AACA"}

main.min.js

var a=[];a.push("a");a.push("b");a.push("c");for(var b=0,b=0;b<a.length;b++)print(a[b]);

main.min.js.map

{
"version":3,
"file":"main.min.js",
"lineCount":1,
"mappings":"AAMA,IAAIA,EAAO,EACXA,EAAAC,KAAA,CAAU,GAAV,CACAD,EAAAC,KAAA,CAAU,GAAV,CACAD,EAAAC,KAAA,CAAU,GAAV,CAPE,KADA,IAAIC,EAAI,CAAR,CACKA,EAAI,CAAT,CAAYA,CAAZ,CAQGF,CARaG,OAAhB,CAA6BD,CAAA,EAA7B,CACEE,KAAA,CAOCJ,CAPK,CAAKE,CAAL,CAAN;",
"sources":["main.js"],
"names":["list","push","i","length","print"]
}