How do nested variables within the .env file work in CodeIgniter 4

How do nested variables within the .env file work in CodeIgniter 4 - Printable Version

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How do nested variables within the .env file work in CodeIgniter 4 - Dozor - 06-30-2020

Under the "Nesting Variables" section in the CI4 documentation under General Topics -> Configuration:

"To save on typing, you can reuse variables that you’ve already specified in the file by wrapping the variable name within ${...}"

example in the documentation:

Code:
BASE_DIR="/var/webroot/project-root"

CACHE_DIR="${BASE_DIR}/cache"

TMP_DIR="${BASE_DIR}/tmp"

I was trying to use the following

Code:
app.baseURL = 'http://localhost:8080/'

google.redirect = ${app.baseURL}Google

However, it's assigning it as a literal when print_r($_ENV)

Code:
[google.redirect] => ${app.baseURL}Google

I've tried using non-namespaced keys including BASE_DIR (per the example) and it keeps printing as a literal.

What's strange - When I use the following:

Code:
CI_ENVIRONMENT = development

google.redirect = ${CI_ENVIRONMENT}Google

The result when print_r is:

Code:
[CI_ENVIRONMENT] => development

[google.redirect] => developmentGoogle

My question is - What am I doing incorrectly and/or how should these be set/used correctly?

According to the documentation, It makes it seem like I should be able to use any key within the .env file that was already assigned using

${somekeyinthisenvfile}

CI version: 4.0.3
PHP 7.4.0

Using CI CLI

RE: How do nested variables within the .env file work in CodeIgniter 4 - Dozor - 06-30-2020

To add onto this:

I've tried the following

Code:
CI_ENVIRONMENT = development

x = test

somerandomvariablename = foo

control = ${CI_ENVIRONMENT}

google.redirect1 = ${x}GoogleLogin

google.redirect2 = ${somerandomvariablename}GoogleLogin

justatestwithnodotinvarname = ${somerandomvariablename}GoogleLogin

Which produces the following in print_r($_ENV):

Code:
[CI_ENVIRONMENT] => development

[x] => test

[somerandomvariablename] => foo

[control] => development

[google.redirect1] => ${x}GoogleLogin

[google.redirect2] => ${somerandomvariablename}GoogleLogin

[justatestwithnodotinvarname] => ${somerandomvariablename}GoogleLogin

RE: How do nested variables within the .env file work in CodeIgniter 4 - Dozor - 06-30-2020

Looks like the DotEnv.php file from composer was outdated.

answer from StackOverflow:
https://stackoverflow.com/questions/62648655/how-do-nested-variables-within-the-env-file-work-in-codeigniter-4