bump and unbump share environment variable object

[zsstiers]

The bump and unbump tasks interfere with each other's environment variables. For example, if you do

project.tasks.tryFind("bump")?.env("EXAMPLE", "foo");

you will find that "EXAMPLE": "foo" appears in both the bump and unbump tasks in tasks.json.

This becomes problematic when wanting to set the same environment variable to different values. For example, if you desired to do

project.tasks.tryFind("bump")?.env("STEP_NAME", "bump");
project.tasks.tryFind("unbump")?.env("STEP_NAME", "unbump");

you'd find that "STEP_NAME" is "unbump" in both cases.

I'm not sure what the intended behavior of

const env = {};
project.addTask("example", {
  exec: 'echo "Hello world"',
  env,
});
env.EXAMPLE = "foo";

is though, so I'm not sure what the most appropriate fix is.

If the intended behavior is that EXAMPLE has been added to the task then I think the fix is to replace env: env with env: { ...env } in at least one of the locations in https://github.com/projen/projen/blob/main/src/version.ts#L105-L117.

If the intended behavior is that EXAMPLE is not added then I think the fix is for https://github.com/projen/projen/blob/main/src/task.ts#L63 to be this._env = { ...props.env };. This second approach would imply the need for similar changes to conditions, steps, and requiredEnv though.