pacman: Fail fast when 'rc != 0'

We fail-fast and display 'stderr' in case 'pacman' returns with 'rc != 0'.
There is no point computing 'module._diff' in such case anyway.

Fixes #23910

lib/ansible/modules/packaging/os/pacman.py

@@ -256,6 +256,9 @@ def remove_packages(module, pacman_path, packages):
         cmd = "%s -%s %s --noconfirm --noprogressbar" % (pacman_path, args, package)
         rc, stdout, stderr = module.run_command(cmd, check_rc=False)
 
+        if rc != 0:
+            module.fail_json(msg="failed to remove %s" % (package))
+
         if module._diff:
             d = stdout.split('\n')[2].split(' ')[2:]
             for i, pkg in enumerate(d):
@@ -263,9 +266,6 @@ def remove_packages(module, pacman_path, packages):
                 diff['before'] += "%s\n" % pkg
             data.append('\n'.join(d))
 
-        if rc != 0:
-            module.fail_json(msg="failed to remove %s" % (package))
-
         remove_c += 1
 
     if remove_c > 0:
@@ -303,6 +303,10 @@ def install_packages(module, pacman_path, state, packages, package_files):
     if to_install_repos:
         cmd = "%s -S %s --noconfirm --noprogressbar --needed" % (pacman_path, " ".join(to_install_repos))
         rc, stdout, stderr = module.run_command(cmd, check_rc=False)
+
+        if rc != 0:
+            module.fail_json(msg="failed to install %s: %s" % (" ".join(to_install_repos), stderr))
+
         data = stdout.split('\n')[3].split(' ')[2:]
         data = [ i for i in data if i != '' ]
         for i, pkg in enumerate(data):
@@ -310,14 +314,15 @@ def install_packages(module, pacman_path, state, packages, package_files):
             if module._diff:
                 diff['after'] += "%s\n" % pkg
 
-        if rc != 0:
-            module.fail_json(msg="failed to install %s: %s" % (" ".join(to_install_repos), stderr))
-
         install_c += len(to_install_repos)
 
     if to_install_files:
         cmd = "%s -U %s --noconfirm --noprogressbar --needed" % (pacman_path, " ".join(to_install_files))
         rc, stdout, stderr = module.run_command(cmd, check_rc=False)
+
+        if rc != 0:
+            module.fail_json(msg="failed to install %s: %s" % (" ".join(to_install_files), stderr))
+
         data = stdout.split('\n')[3].split(' ')[2:]
         data = [ i for i in data if i != '' ]
         for i, pkg in enumerate(data):
@@ -325,9 +330,6 @@ def install_packages(module, pacman_path, state, packages, package_files):
             if module._diff:
                 diff['after'] += "%s\n" % pkg
 
-        if rc != 0:
-            module.fail_json(msg="failed to install %s: %s" % (" ".join(to_install_files), stderr))
-
         install_c += len(to_install_files)
 
     if state == 'latest' and len(package_err) > 0: