Passing command to bash from cmd.exe (WSL) not working

Question

I'm on a Windows 10 machine with Windows Subsystem for Linux enabled/configured (Ubuntu). To explain my problem let me present you with two scenarios:

Scenario 1:

1. I start a cmd.exe prompt
2. I run bash in the cmd.exe prompt
3. (inside bash) I run a given command, called dwiextract in my case (from a neuroimaging analysis software package)

Works fine suggesting a successful installation of the software package.

Scenario 2:

1. I start a cmd.exe prompt
2. I attempt to pass the exact same command directly to bash from cmd.exe by using the following syntax: bash -c dwiextract

I get command not found.

(Note I learned about bash -c here and have used it successfully in other occasions.)

The following image shows exactly what I've done:

My question: Shouldn't these two scenarios be equivalent. Why does Scenario 1 work and Scenario 2 does not work?

Many thanks.

Solution

Running bash as an interactive shell (using -i option) solved my problem.

That is: bash -c -i <command>.

Comments

[smw]

Likely related: bash -c and noninteractive shell

[fnery]

Running bash as an interactive shell (using -i option) solved my problem. Thanks steeldriver.

[Kusalananda]

... because the $PATH was not the same in the two shells, and starting an interactive shell forces bash to read the bashrc file, where the PATH is set.

[BSalita]

I had to use exactly this: wsl -d Ubuntu-20.04 -u robert bash -c -i "cd /mnt/c/fastai2 && conda activate fastai2 && jupyter lab"

[Jiri Otoupal イり オトウパー]

I had tried all options from this thread and nothing works still it says: /bin/bash Command not found