GHC installation doesn't work from root folder

[varosi]

General summary/comments (optional)

Steps to reproduce

For example:

1. Put in the root of some drive (D:) ghc archive
2. Copy yaml file:

sevenzexe-info:
    url: "https://github.com/fpco/minghc/blob/master/bin/7z.exe?raw=true"
    content-length: 73728
    sha1: 187dff8a3327da87050f678579816e5bae40c632
sevenzdll-info:
    url: "https://github.com/fpco/minghc/blob/master/bin/7z.dll?raw=true"
    content-length: 447488
    sha1: 168a288d4456f0473f66e86a2d6fec4eb6f4b993
msys2:
    windows64:
        version: "20150512"
        url: "https://github.com/fpco/minghc/releases/download/2015-05-14/msys2-base-x86_64-20150512.tar.xz"
        content-length: 33451040
        sha1: 88fa66ac2a18715a542e0768b1af9b2f6e3680b2
ghc:
    windows64-integersimple:
        8.0.2:
            url: "D:/ghc-8.0.2-x86_64-unknown-mingw32-integer-simple.tar.xz"

3. Run 'stack setup --stack-setup-yaml stack-setup-2.yaml --reinstall --ghc-variant integersimple'

Expected

To work as it is working if GHC archive is moved into a folder D:\ttt\

Stack version

stack --version
Version 1.4.1, Git revision ea10057da1b1a49d937e7bcb6f997360bec1f863 (4765 commits) x86_64 hpack-0.17.0

[lwm]

Hi @varosi, what is the error you are seeing?

I dug around and saw that it should be fine with absolute paths.

[varosi]

7-Zip 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18

Processing archive: D:\ghc-8.0.2-x86_64-unknown-mingw32-integer-simple.tar.xz


Error: Can not create output directory D:\\


System error:
The filename, directory name, or volume label syntax is incorrect.

Problem while decompressing D:\ghc-8.0.2-x86_64-unknown-mingw32-integer-simple.tar.xz

[mgsloan]

Looks to me like a bug in 7zip, or perhaps it expects the -o argument to be different. Not sure if stack is passing in D: or D:\.

I've pushed a potential fix - #3212 - please let me know if it works.

[varosi]

I think that the real problem is that it tries to create root folder in D:\ which will not work. See the error message

Error: Can not create output directory D:\

I don't know why it tries to do that.

[mgsloan]

@varosi Sorry for the delay! Yes, that is a 7zip error message - https://stackoverflow.com/questions/43039683/cannot-create-output-directory-error-7zip

[varosi]

No problem!

[mgsloan]

@varosi I haven't merged #3212 yet, does it fix the problem?

[varosi]

@mgsloan It works with your changes!

[mgsloan]

Great, thanks for the confirmation!