fix output from runners to IOBuffer

Author: KristofferC

src/Runner.jl

@@ -3,6 +3,8 @@ abstract type Runner; end
 
 export default_host_platform
 
+const AnyRedirectable = Union{Base.AbstractCmd, Base.TTY, IOStream, IOBuffer}
+
 # Host platform _must_ match the C++ string ABI of the binaries we get from the
 # repositories.  Note: when preferred_gcc_version=v"4" we can't really build for
 # that C++ string ABI :-(

src/UserNSRunner.jl

@@ -182,7 +182,6 @@ function Base.read(ur::UserNSRunner, cmd; verbose=false)
     return collect_stdout(oc)
 end
 
-const AnyRedirectable = Union{Base.AbstractCmd, Base.TTY, IOStream}
 function run_interactive(ur::UserNSRunner, user_cmd::Cmd; stdin = nothing, stdout = nothing, stderr = nothing, verbose::Bool = false)
     warn_priviledged()
 

test/runners.jl

@@ -322,3 +322,10 @@ end
         end
     end
 end
+
+@testset "outptut runner" begin
+    io = IOBuffer()
+    run_interactive(BinaryBuilderBase.preferred_runner()(mktempdir(); platform=Platform("x86_64", "linux"; libc="musl")), `/bin/bash -c "echo \$PATH"`, stdout=io)
+    s = String(take!(io))
+    @test !isempty(s)
+end