How to import a URL with a space?

I’ve read a lot about this and if I got it correctly, Dhall support this since 2018 and back then the solution was to quote the component of the path containing a space. However, testing this with the Haskell implementation of dhall, version 1.40.2 and also 1.41.2 gives an error message:

> dhall <<< `https://api.github.com/repos/account/repo/contents/templates/"mat cat"/file.dhall using [...]`

dhall-1.41.2: 
Error: Invalid input

(input):1:74:
  |
1 | https://api.github.com/repos/account/repo/contents/templates/"mat cat"/file.dhall using [...]
unexpected '"'
expecting "→", "∧", "≡", "⩓", "⫽", '%', '/', '?', --, ->, //, //\\, /\, :, ===, end of input, keyword, operator, or whitespace

So I looked into the source code and found out that:

pathComponent :: ComponentType -> Parser Text
pathComponent componentType = do
    ...
    case componentType of
        FileComponent -> quotedPathData <|> pathData
        URLComponent -> pathData

quoted paths are only allowed for file path components. I also found a blog post that quoted paths were deprecated and one should use % escaping instead. I guess the correct way to code a space in a URL is %20, but I can’t get it to work:

> dhall repl
Welcome to the Dhall v1.41.2 REPL! Type :help for more information.
⊢ https://api.github.com/repos/account/repo/contents/templates/mat%20cat/file.dhall using [...]

Error: Remote file not found

HTTP status code: 404

URL: https://api.github.com/repos/account/repo/contents/templates/mat%2520cat/file.dhall

Message:

1│ {"message":"Not Found","documentation_url":"https://docs.github.com/rest/reference/repos#get-repository-content"}

Why is my %20 converted to %2520? I couldn’t find the code that did this. Dhall 1.40.2 behaves the same. Is this a bug or am I doing it wrongly?

That seems like a bug. Could you open an issue?