Yarn does not work in Git Bash on Windows

[Yagun]

Windows 7
Yarn 1.3.2 (the same issue with 1.1.0)
Git 2.16.1.windows.4

The path to Yarn is in the Environment PATH variable: D:\Program Files (x86)\Yarn\bin

Yarn works in Windows cmd.exe and PowerShell console. For example:
c:>yarn --version

But does not work in Git Bash:
$ yarn --version

module.js:538
throw err;
^

Error: Cannot find module 'C:\Program Files\Git\yarn.js'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Function.Module.runMain (module.js:676:10)
at startup (bootstrap_node.js:187:16)
at bootstrap_node.js:608:3

I restarted Windows after yarn installation.

[torifat]

What is the output of which yarn in Git Bash?

[Yagun]

/d/Program Files (x86)/Yarn/bin/yarn

[Yagun]

Just found that yarn.cmd command works.

For example:
$ yarn.cmd --version
1.3.2

But:
$ yarn --version
module.js:538
throw err;
^
Error: Cannot find module 'C:\Program Files\Git\yarn.js'

[torifat]

And, what is the output of which yarn.cmd?

[Yagun]

$ which yarn.cmd

which: no yarn.cmd in (/c/Users/USERNAME_HERE/bin:/mingw64/bin:/usr/local/bin:/usr/bin:/bin:/mingw64/bin:/usr/bin:/c/Users/USERNAME_HERE/bin:/d/Program Files/Python35/Scripts:/d/Program Files/Python35:/c/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v8.0/lib/x64:

... (lots of paths here) ...

/d/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin:/d/Caffe/python:/cmd:/d/Program Files (x86)/Yarn/bin:/c/Users/USERNAME_HERE/AppData/Local/Yarn/bin:/c/Users/USERNAME_HERE/AppData/Roaming/npm:/c/Users/USERNAME_HERE/AppData/Local/Yarn/bin:/usr/bin/vendor_perl:/usr/bin/core_perl)

[torifat]

This doesn't seem like a problem with Yarn. Try adding it to PATH in ~/.bash_profile.

[Yagun]

Well, other things like npm and nodejs work fine. Only yarn does not.

I added the path to yarn to PATH to the profile this way:
PATH=$PATH':/d/Program Files (x86)/Yarn/bin'

The error message is still the same.

[imudak]

The same problem has occurred in msys2. I run msys2 on Windows 8.1.

$ yarn
module.js:559
    throw err;
    ^

Error: Cannot find module 'C:\yarn.js'
    at Function.Module._resolveFilename (module.js:557:15)
    at Function.Module._load (module.js:484:25)
    at Function.Module.runMain (module.js:703:10)
    at startup (bootstrap_node.js:193:16)
    at bootstrap_node.js:665:3

I edited the yarn script and confirmed it.
It seems to be caused by the result of sed becoming empty character.

$ cat /c/Program\ Files\ \(x86\)/Yarn/bin/yarn
#!/bin/sh
echo "0: $0"
argv0=$(echo "$0" | sed -e 's,\\,/,g')
echo "argv0: $argv0"
basedir=$(dirname "$(readlink "$0" || echo "$argv0")")
echo "basedir: $basedir"
...

[result]
$ yarn
0: /c/Program Files (x86)/Yarn/bin/yarn
argv0:
basedir: .

I do not know why it will be empty.
Tentatively, replacing sh with zsh worked fine.

$ cat /c/Program\ Files\ \(x86\)/Yarn/bin/yarn
#!/bin/zsh
...

$ yarn --version
1.3.2

[imudak]

The cause was found out. This is caused by MacType.
https://sourceforge.net/p/msys2/discussion/general/thread/aa858e3e/

Please uninstall MacType and try it.

[Yagun]

I do not have MacType on my PC. So, in my case Yarn issue is not related to MacType.

[emilchristensen]

Same issues replicated on a freshly installed Windows 10 Pro 64-bit machine:

Git for windows 2.16.2-64-bit (Also tried with 2.15.x)
NVM for Windows 1.1.6 (Also tried with 1.1.5)
Yarn 1.5.1 (Also tried with 1.3.2)

When run from cmd.exe:

C:\Users\echristensen>yarn --version
1.5.1

When run from Powershell:

PS C:\Users\echristensen> yarn --version
1.5.1

When run from Git Bash (MINGW64):

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ yarn --version
module.js:478
    throw err;
    ^

Error: Cannot find module 'C:\Users\echristensen\yarn.js'
    at Function.Module._resolveFilename (module.js:476:15)
    at Function.Module._load (module.js:424:25)
    at Module.runMain (module.js:611:10)
    at run (bootstrap_node.js:387:7)
    at startup (bootstrap_node.js:153:9)
    at bootstrap_node.js:500:3

The funny thing is that it works if I run the js file directly or the cmd from Git Bash:

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ yarn.js --version
1.5.1

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ yarn.cmd --version
1.5.1

[emilchristensen]

Bonus information:
Git for Windows:

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ which yarn
/c/Program Files (x86)/Yarn/bin/yarn

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ which yarn.js
/c/Program Files (x86)/Yarn/bin/yarn.js

echristensen@ECHRISTENSEN-PC MINGW64 ~
$ which yarn.cmd
which: no yarn.cmd in (/c/Users/echristensen/bin:/mingw64/bin:/usr/local/bin:/usr/bin:/bin:/mingw64/bin:/usr/bin:/c/Users/echristensen/bin:/c/Python27:/c/Python27/Scripts:/c/WINDOWS/system32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell/v1.0:/c/Program Files/dotnet:/c/Program Files/Microsoft SQL Server/130/Tools/Binn:/cmd:/c/Program Files (x86)/Yarn/bin:%NVM_HOME%:%NVM_SYMLINK%:/c/Users/echristensen/AppData/Local/Microsoft/WindowsApps:/c/Users/echristensen/AppData/Local/Yarn/bin:/c/Users/echristensen/AppData/Roaming/npm:/c/Users/echristensen/AppData/Roaming/nvm:/c/Program Files/nodejs:/usr/bin/vendor_perl:/usr/bin/core_perl)

cmd.exe:

C:\Users\echristensen>where yarn
C:\Program Files (x86)\Yarn\bin\yarn
C:\Program Files (x86)\Yarn\bin\yarn.cmd
C:\Program Files (x86)\Yarn\bin\yarn.js