Nim/doc/basicopt.txt

::

    nim command [options] [projectfile] [arguments]

Command:
  //compile, c              compile project with default code generator (C)
  //r                       compile to $nimcache/projname, run with [arguments]
                            using backend specified by `--backend` (default: c)
  //doc                     generate the documentation for inputfile for
                            backend specified by `--backend` (default: c)

Arguments:
  arguments are passed to the program being run (if --run option is selected)

Options:
  -p, --path:PATH           add path to search paths
  -d, --define:SYMBOL(:VAL)
                            define a conditional symbol
                            (Optionally: Define the value for that symbol,
                            see: "compile time define pragmas")
  -u, --undef:SYMBOL        undefine a conditional symbol
  -f, --forceBuild:on|off   force rebuilding of all modules
  --stackTrace:on|off       turn stack tracing on|off
  --lineTrace:on|off        turn line tracing on|off
  --threads:on|off          turn support for multi-threading on|off
  -x, --checks:on|off       turn all runtime checks on|off
  -a, --assertions:on|off   turn assertions on|off
  --opt:none|speed|size     optimize not at all or for speed|size
                            Note: use -d:release for a release build!
  --debugger:native         Use native debugger (gdb)
  --app:console|gui|lib|staticlib
                            generate a console app|GUI app|DLL|static library
  -r, --run                 run the compiled program with given arguments
  --fullhelp                show all command line switches
  -h, --help                show this help
  -v, --version             show detailed version information

Note, single letter options that take an argument require a colon. E.g. -p:PATH.