Generate a shell script with environment variables and commands when build fail

To make it easyier to diagnose build errors.

slapos/recipe/cmmi/README.txt

@@ -1083,7 +1083,10 @@ If no shared-parts is set, and shared is True, shared feature is not used:
     building package
     installing package
 
-If shared-parts is set and shared is True, build package failed, the build directory is removed, a build directory__complile__ is left for debugging
+If shared-parts is set and shared is True, build package failed, the build directory is removed,
+a build directory__compile__ is left for debugging.
+Also a shell script with the environment variable is created, so that developer can try same build
+process as the recipe tried.
     >>> _ = system('mv %s/package-0.0.0.tar.gz  %s/package-0.0.0.tar.gz.bak' % (src, src))
     >>> import tarfile
     >>> from io import BytesIO
@@ -1106,21 +1109,29 @@ If shared-parts is set and shared is True, build package failed, the build direc
     ... recipe = slapos.recipe.cmmi
     ... url = file://%s/package-0.0.0.tar.gz
     ... shared = True
+    ... environment =
+    ...   FOO=bar
     ... """ % (shared_dir, src))
     >>> print system(buildout) #doctest:+ELLIPSIS
     package: shared directory  .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/... set for package
     Uninstalling package.
     Installing package.
     package: Checking whether package is installed at shared path: .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/...
+    package: [ENV] FOO = bar
     package: [ENV] TEMP = .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/.../tmp
     package: [ENV] TMP = .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/.../tmp
     package: [ENV] TMPDIR = .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/.../tmp
     package: Command failed with exit code 127: ./configure --prefix=".../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/..."
-    package: Compilation error. The package is left as is at .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/...__compile__ where you can inspect what went wrong
+    package: Compilation error. The package is left as is at .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/...__compile__ where you can inspect what went wrong.
+    A shell script slapos.recipe.build.env.sh has been generated. You can source it in your shell to reproduce build environment.
     /bin/sh: 1: ./configure: not found
     While:
       Installing package.
     Error: System error
+    >>> import glob
+    >>> cat(glob.glob(os.path.join(shared_dir, 'package/**__compile__/slapos.recipe.build.env.sh'))[0])
+    export FOO="bar"
+    ...
 
 If shared-parts is set and shared is True, package will be installed in shared_part/package/a hash of the recipe's configuration options
     >>> _ = system('mv %s/package-0.0.0.tar.gz.bak  %s/package-0.0.0.tar.gz' % (src, src))
@@ -1149,7 +1160,9 @@ Do nothing if one package has been installed.
     ... recipe = slapos.recipe.cmmi
     ... url = file://%s/package-0.0.0.tar.gz
     ... shared = True
-    ... """ % (shared_dir, src))   
+    ... environment =
+    ...   FOO=bar
+    ... """ % (shared_dir, src))
     >>> print system(buildout) #doctest:+ELLIPSIS
     package: shared directory  .../slapos.recipe.cmmi/slapos/recipe/cmmi/shared/package/... set for package
     Installing package.

slapos/recipe/cmmi/__init__.py

@@ -408,8 +408,24 @@ class Recipe(object):
                     log.info('Getting installed file lists')
                     parts.extend(self.get_installed_files(tmp_path))
             except:
+
+                with open('slapos.recipe.build.env.sh', 'w') as env_script:
+                    for key, v in sorted(self.environ.items()):
+                        if key not in ('TEMP', 'TMP', 'TMPDIR'):
+                            env_script.write('export %s="%s"\n' % (key, v))
+                    env_script.write('echo "If this recipe does not use pre/post hooks or commands, you can re-run as below."\n')
+                    env_script.write('echo "configure with:"\n')
+                    env_script.write('echo "   %s %s"\n' % (configure_cmd, ' '.join(configure_options)) % self.options)
+                    env_script.write('echo ""\n')
+                    env_script.write('echo "make with:"\n')
+                    env_script.write('echo "  %s %s"\n' % (make_cmd, make_options) % self.options)
+
+
                 log.error('Compilation error. The package is left as is at %s where '
-                          'you can inspect what went wrong' % os.getcwd())
+                          'you can inspect what went wrong.\n'
+                          'A shell script slapos.recipe.build.env.sh has been generated. '
+                          'You can source it in your shell to reproduce build environment.' % os.getcwd())
+
                 # Delete shared directory if not correctly installed
                 if self.options.get('shared'):
                     shutil.rmtree(self.options['shared'])