How to set additional environment variables for new process in typed-process?

Question

I'd like a new process to inherit the existing environment variables, as well as set my own.

I only see two options to set the environment variables within http://hackage.haskell.org/package/typed-process-0.2.6.0/docs/System-Process-Typed.html:

setEnv :: [(String, String)] -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderrSource
setEnvInherit :: ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr

I could manually get a list of all environment variables with System.Environment.getEnvironment however it's documentation(http://hackage.haskell.org/package/base-4.12.0.0/docs/System-Environment.html#v:getEnvironment) mentions:

getEnvironment retrieves the entire environment as a list of (key,value) pairs.

If an environment entry does not contain an '=' character, the key is the whole entry and the value is the empty string.

Which seems a bit iffy.

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Looking through the source there seems to be a data constructor that has the environment variables set in pcEnv :: !(Maybe [(String, String)]) - but this does not seem to be exported. Is there some means to modify this value?

Answer 1

One workaround can be done using the unix package:

import System.Posix.Env (getEnvironment)

currentEnv <- getEnvironment
let totalEnv = currentEnv ++ [("KUBECONFIG","k8s.cfg")]