is env variable referencing supported?

I've stumbled on this thread because I'm having the same issue, and after trying numerous different approaches, I'm left wondering why this doesn't work.

Let's start with a simple example that uses https://developer.1password.com/docs/cli/secrets-template-syntax#enclosed-secret-references:

.env


DATABASE_URL="http://{{op://private/my_app/username}}:{{op://private/my_app/password}}@localhost:1234"


Checking this with op inject returns the expected result, with the two secret refs replaced with the values "bob" and "secret" respectively; but running through op run and printenv doesn't:

```
$ op inject -i .env
DATABASE_URL="http://bob:secret@localhost:1234"

$ op run --env-file=.env --no-masking -- printenv DATABASE_URL
http://{{op://private/my_app/username}}:{{op://private/my_app/password}}@localhost:1234
```

So it seems that constructing an ENV value by embedding enclosed secret refs into a string doesn't work.

Let's try a different approach using multiple ENV vars:

.env


USERNAME="op://private/my_app/username"
PASSWORD="op://private/my_app/password"
DATABASE_URL="http://${USERNAME}:${PASSWORD}@localhost:1234"


```
$ op inject -i .env

USERNAME=bob
PASSWORD=secret
DATABASE_URL="http://${USERNAME}:${PASSWORD}@localhost:1234"

$op run --env-file=.env --no-masking -- printenv USERNAME
bob

$op run --env-file=.env --no-masking -- printenv PASSWORD
secret

$ op run --env-file=.env --no-masking -- printenv DATABASE_URL
http://op://private/my_app/username:op://private/my_app/password@localhost:1234
```

Again, we can see that op inject seems to have correctly substituted the USERNAME and PASSWORD values, and left DATABASE_URL unchanged (with the assumption that they would be correctly expanded when a process tries to read $DATABASE_URL).

We can also see that op run has correctly resolved the USERNAME and PASSWORD vars, but now DATABASE_URL has been substituted with....the secret refs?

(I've tried this this with/without quotes, with/without curly braces etc. Nothing seems to work).

One more, just to really confuse things:

.env


USERNAME="op://private/my_app/username"
PASSWORD="op://private/my_app/password"
DATABASE_USERNAME="${USERNAME}"
DATABASE_PASSWORD="${PASSWORD}"


```
$ op inject -i .env
USERNAME="bob"
PASSWORD="secret"
DATABASE_USERNAME="${USERNAME}"
DATABASE_PASSWORD="${PASSWORD}"

$ op run --env-file=.env --no-masking -- printenv DATABASE_USERNAME

bob

$ op run --env-file=.env --no-masking -- printenv DATABASE_PASSWORD
secret
```

Wait, what? That works?

Here we have two ENV vars ($DATABASE_USERNAME and $DATABASE_PASSWORD) that reference to other ENV vars ($USERNAME and $PASSWORD) that are using secret refs....and it all works fine?

The difference here seems to be referencing a $VAR on its own ("${USERNAME}") is fine, but referencing it inside a string ("xx${USERNAME}") is not?

It seems like this should all just work.