One line installer script not working in git-bash nor in power-shell

[hohwille]

Actual behavior

I tested the one-line installer (see #1795) in git-bash and got this error:

Error: Unsupported operating system: MINGW64_NT-10.0-26200. Use the PowerShell installer on Windows.

I then reran the same command in PowerShell and got this error:

Invoke-WebRequest : A parameter cannot be found that matches parameter name 'fsSL'.
At line:1 char:17
+ bash -c "$(curl -fsSL https://raw.githubusercontent.com/devonfw/IDEas ...
+                 ~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Invoke-WebRequest], ParameterBindingException
    + FullyQualifiedErrorId : NamedParameterNotFound,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

<3>WSL (9 - Relay) ERROR: CreateProcessCommon:798: execvpe(/bin/bash) failed: No such file or directory

Reproduce

bash -c "$(curl -fsSL https://raw.githubusercontent.com/devonfw/IDEasy/main/install.sh)"

Expected behavior

The benefit of the new "one line installer" script should be to simplify the installation of IDEasy.
Therefore, it should just work and not cause such complications.

IDEasy status

not applicable (tested with 2026.04.001)

Related/Dependent issues

#1795

Comments/Hints

To properly detect OS in bash see our old code from devonfw-ide:
https://github.com/devonfw/ide/blob/855ce79d795860416f73634397ea9a535c27a68c/scripts/src/main/resources/scripts/functions#L1776-L1790

[shodiBoy1]

@hohwille the issue was in detect_os() it didnt handle git bash on windows. uname -s returns MINGW64_NT-... in git bash which hit the catch-all and threw the error

fix: added MINGW*|MSYS*|CYGWIN* pattern to detect windows git bash.

tested on windows works fine now including full setup and license prompt.

for PowerShell: since git is a prerequisite, git bash is always available on windows, so users should just run the command there instead.

#1798