#9785 feat: Treat dotenv null values (e.g. `ENV_VAR` without a value) not as missing, but as "unsetting" Issue created by edgarrmondragon ### Meltano Version 4.0.9 ### Python Version NA ### Bug scope Configuration (settings parsing, validation, etc.) ### Operating System NA ### Description The

dotenv_values

function from the

python-dotenv

package can be set to `None`[^1]:

### Variable without a value

A variable can have no value:

FOO

It results in

dotenv_values

associating that variable name with the value

None

(e.g.

{"FOO": None}

.

load_dotenv

, on the other hand, simply ignores

such variables.

This shouldn't be confused with

FOO=

, in which case the variable is associated

with the empty string.

This means that if we have the following

meltano.yml

and

.env

plugins: extractors: - name: tap-pypistats variant: edgarrmondragon pip_url: tap-pypistats config: packages: - tap-$TAP_NAME TAP_NAME produce this behavior during env var expansion $ meltano --log-level warning config print tap-pypistats { "packages": [ "tap-None" ] } ### Decision • Should we treat

None

as the empty string? i.e.

ENV_VAR

is the same as

ENV_VAR=

. Update: this was done in #9825 • More interestingly: should

ENV_VAR

and its null value override lower-precedence setting stores, e.g. having

TAP_MY_SETTING

in

.env

and

my_setting: val

in

meltano.yml

will result in

my_setting

being set to null, i.e. unset (#6382, #2510). ### Related • #2510 • #6382 • #9825 ### Code plugins: extractors: - name: tap-pypistats variant: edgarrmondragon pip_url: tap-pypistats config: packages: - tap-$TAP_NAME ### Link to Slack/Linen No response meltano/meltano