Executing a D script without an [extension in the filename] leads to an error

[BoQsc]

On Friday, 1 March 2019 at 09:27:33 UTC, Cym13 wrote:
> On Friday, 1 March 2019 at 09:00:43 UTC, BoQsc wrote:
>> I've installed D compiler, and when i try to run a D script 
>> with filename without an extension/file type named: program
>>
>> via: ./program
>>
>> I'm getting and error:
>>
>> vaidas at SATELLITE-L855:~/Desktop$ ./program
>> Error: module `program` is in file './program.d' which cannot 
>> be read
>> import path[0] = .
>> import path[1] = /snap/dmd/49/bin/../import/druntime
>> import path[2] = /snap/dmd/49/bin/../import/phobos
>> Failed: ["/snap/dmd/49/bin/dmd", "-v", "-o-", "./program.d", 
>> "-I."]
>>
>>
>> Now, when I rename my scirpt file : program
>> To: program.d
>>
>> and execute it by: ./program.d
>>
>> I no longer have an error.
>>
>> Is this an intended behaviour?
>
> In such questions it's important to show your shebang since 
> that's what runs your script.
>
> Given your symptoms I guess you're using the following:
>
> #!/bin/env rdmd
>
> And indeed rdmd won't call your script if it doesn't have the 
> proper extension.
>
> Try using this instead:
>
> #!/bin/dmd -run

The shebang I used: #!/usr/bin/env rdmd

I was visiting Dlang Tour and that's where I've got an example of 
shebang usage, directly from there:
https://tour.dlang.org/tour/en/welcome/run-d-program-locally#/on-the-fly-compilation-with-rdmd

The shebang you suggested actually works perfectly:
#!/bin/dmd -run


"And indeed rdmd won't call your script if it doesn't have the 
proper extension."

Then why does Dlang Tour includes shebang: #!/usr/bin/env rdmd

Instead of the one you mentioned, that is fool proof. (#!/bin/dmd 
-run)

Is that an error/mistake in Dlang Tour guide?