Midphase
So why the need for a specific variable at all? Seems to me like simpler is always better. Am I wrong?

Midphase
Is there any way that I could set this as a .json package instead (hence leaving the Houdini.env file completely alone)?

Midphase
I do like what 3Delight installer does which is actually automatically configure the .json file without needing the user to ever go into a text editor to change it. It just works!

{
    "enable": true,
    "env": [
        {
            "DELIGHT": "C:/Program Files/3Delight"
        }, 
        {
            "PATH": {
                "method": "append", 
                "value": [
                    "$DELIGHT/bin"
                ]
            }
        },
        {
            "HOUDINI_PATH": {
                "method": "append", 
                "value": [
                    "$DELIGHT/houdini/18.0"
                ]
            }
        },
        {
            "HOUDINI_SCRIPT_PATH": {
                "method": "prepend",
                "value": [
                    "$DELIGHT/houdini/18.0/scripts"
                ]
            }
        },
        {
            "HOUDINI_SOHO_PATH": {
                "method": "prepend",
                "value": [
                    "$DELIGHT/houdini/18.0/soho"
                ]
            }
        },
    ]
}

{ "env": [ { "DELIGHT":"C:\\Program Files\\3Delight" }, { "HOUDINI_PATH":"$DELIGHT\\houdini\\18.0" }, { "HOUDINI_SCRIPT_PATH":"$DELIGHT\\houdini\\18.0\\scripts" }, { "HOUDINI_SOHO_PATH":"$DELIGHT\\houdini\\18.0\\soho" } ] }

toadstorm
Regarding the MOPS variable in your example package, I use that in other accessory scripts to help with the automatic updater, among other things. It isn't strictly necessary but it makes it a lot easier for me to know where the MOPs HDAs are on a user's system when I'm expanding or collapsing HDA definitions, for example.

Package files, confusingly, have a lowercase “path” key that you can set outside of the “env” object. This “path” in reality is referring to HOUDINI_PATH. If you want to set the system PATH variable, you'd have to create a variable named PATH inside the “env” object in your package.

I did a bit more explaining on the quirks of packages here: https://www.toadstorm.com/blog/?p=722 [www.toadstorm.com]

{
    "path" : "foo2",
    "env" :
    [
        {"HOUDINI_PATH" : "foo1"}
    ]
}

. hconfig -xa
HOUDINI_OS := 'Windows'
HOUDINI_PATH := 'foo1;foo2;&'
HOUDINI_USER_PREF_DIR := 'C:/Users/marcb/houdini18.0'

Unlike under the path key, under env the default is to set a variable, rather than prepend to a path.

“Worse still, it automatically assumes that you're using the append method, whereas the env key assumes you are using the replace method. ”

toadstorm
I'm referring to setting keys in the “env” object that are not Houdini-specific. Houdini's own documentation says that arbitrary environment variables are set by default using “replace” rather than “prepend”:

Unlike under the path key, under env the default is to set a variable, rather than prepend to a path.

So only Houdini-specific variables are automatically given the “prepend” behavior?

Also, regarding this:

“Worse still, it automatically assumes that you're using the append method, whereas the env key assumes you are using the replace method. ”

It's weird that you're seeing “append” there on that post… I corrected that typo almost a month ago to the day. I wonder if it's a cache thing?

Changing “path” to “hpath” seems a good idea to me. Maybe this auto-prepend behavior can be clarified in the documentation so that it's apparent that only Houdini-specific variables receive it?