PSA for RustRover users (that are using '--' arguments)

[SCDevel]

So I was playing around with clap for the first time and started going straight for subcommands with 1 required argument and multiple optional arguments. well every single time I tried a optional argument I would always get:

error: unexpected argument '--arg' found

and assumed that was a generic clap response for a argument not found.
which made me assume I was doing something wrong, so I went through all the docs I could find, trying different things / altering other example to my needs. Everything I tried failed.

So after about 5 hours of trying to get clap to work and seeing many examples of people running cargo with:

cargo run -- Program

I decided to change the default run command in RustRover :

run --package Program --bin Program

which I always changed to:

run --package Program --bin Program subcommand required --arg val

To this:

run -- Program subcommand required --arg val

....5 hours

So I guess since the default command was using optional -- arguments it made cargo think my arguments were its.

So anyone using RustRover might want to consider changing the default run command.

anyway I thought I would give a heads up for anyone that wants to listen to my rant.

[SebastianWojciechowski]

Thanks. Had similar issue.
To explain the -- separates the Cargo-specific options from the program-specific arguments. This means that everything after the -- is passed directly to the application you're running, not to Cargo itself.

[bgasparotto]

Thanks folks, just experienced this today and this saved me a lot of time!