[Windows] ChildProcess::LaunchError: The system cannot find the file specified.

[jawshooah]

When attempting to run a simple echo Hello World command through ChildProcess, somehow the system can't find the echo command, but the Kernel backtick method has no problems:

C:\Users\vagrant>irb
DL is deprecated, please use Fiddle
irb(main):001:0> require 'childprocess'
=> true
irb(main):002:0> `echo Hello World`
=> "Hello World\n"
irb(main):003:0> process = ChildProcess.build('echo', 'Hello', 'World')
=> #<ChildProcess::Windows::Process:0x00000002b761d0 @args=["echo", "Hello", "World"], @started=false, @exit_code=nil, @io=nil, @cwd=nil, @detach=false, @duplex=false, @leader=f
irb(main):004:0> process.start
ChildProcess::LaunchError: The system cannot find the file specified. (2)
        from C:/tools/ruby215/lib/ruby/gems/2.1.0/gems/childprocess-0.5.6/lib/childprocess/windows/process_builder.rb:87:in `create_process'
        from C:/tools/ruby215/lib/ruby/gems/2.1.0/gems/childprocess-0.5.6/lib/childprocess/windows/process_builder.rb:34:in `start'
        from C:/tools/ruby215/lib/ruby/gems/2.1.0/gems/childprocess-0.5.6/lib/childprocess/windows/process.rb:68:in `launch_process'
        from C:/tools/ruby215/lib/ruby/gems/2.1.0/gems/childprocess-0.5.6/lib/childprocess/abstract_process.rb:82:in `start'
        from (irb):5
        from C:/tools/ruby215/bin/irb:11:in `<main>'

[jarib]

ChildProcess doesn't execute your command in a shell like the backtick method does. If that's what you want you should be explicit:

process = ChildProcess.build("cmd.exe", "/c", "echo 'Hello World'")