osbuild: replace api.setup_stdio with BuildRoot

Now that the BuildRoot is capable of capturing the output of the
runner and modules (stages, assemblers), there is no need for
using `api.setup_stdio`. Therefore, drop it from all runners and
replace `api.output` with `BuildRoot.output`, which will contain
the output if `api.setup_stdio` is not called from the runners.

osbuild/pipeline.py

@@ -92,7 +92,7 @@ class Stage:
                                binds=[os.fspath(tree) + ":/run/osbuild/tree"],
                                readonly_binds=ro_binds)
 
-        return BuildResult(self, r.returncode, api.output, api.metadata)
+        return BuildResult(self, r.returncode, r.output, api.metadata)
 
 
 class Assembler:
@@ -151,7 +151,7 @@ class Assembler:
                                binds=binds,
                                readonly_binds=ro_binds)
 
-        return BuildResult(self, r.returncode, api.output, api.metadata)
+        return BuildResult(self, r.returncode, r.output, api.metadata)
 
 
 class Pipeline:

runners/org.osbuild.fedora30

@@ -3,7 +3,6 @@
 import os
 import subprocess
 import sys
-import osbuild.api
 
 
 def ldconfig():
@@ -37,7 +36,6 @@ def nsswitch():
 
 
 if __name__ == "__main__":
-    osbuild.api.setup_stdio()
     ldconfig()
     sysusers()
     tmpfiles()

runners/org.osbuild.linux

@@ -2,11 +2,8 @@
 
 import subprocess
 import sys
-import osbuild.api
 
 
 if __name__ == "__main__":
-    osbuild.api.setup_stdio()
-
     r = subprocess.run(sys.argv[1:], check=False)
     sys.exit(r.returncode)

runners/org.osbuild.rhel81

@@ -3,7 +3,6 @@
 import os
 import subprocess
 import sys
-import osbuild.api
 
 
 def ldconfig():
@@ -71,7 +70,6 @@ def python_alternatives():
         pass
 
 if __name__ == "__main__":
-    osbuild.api.setup_stdio()
     ldconfig()
     sysusers()
     tmpfiles()

runners/org.osbuild.ubuntu1804

@@ -4,8 +4,6 @@ import os
 import subprocess
 import sys
 
-import osbuild.api
-
 
 def ldconfig():
     # ld.so.conf must exist, or `ldconfig` throws a warning
@@ -38,7 +36,6 @@ def nsswitch():
 
 
 if __name__ == "__main__":
-    osbuild.api.setup_stdio()
     ldconfig()
     sysusers()
     tmpfiles()