We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
[bug] Some system packages fail to install (xorg/system, opengl/system)
<!--
  Please don't forget to update the issue title.
  Include all applicable information to help us reproduce your problem.

  To help us debug your issue please explain:
--> When configuring a cmake project template that used conan i encountered an error while configuring cmake : 
`opengl/system: ERROR: while executing system_requirements(): 'SysConfigOpenGLConan' object has no attribute 'warn'`. After attemping a manual installation with `conan install opengl/system@` i still have the same problem and output. I have no idea what could be causing this and after a few hours of googling i failed to find anything that would explain this. I also get the exact same output when installing `xorg/system`

### Environment Details (include every applicable attribute)
  * Operating System+version: Pop!_OS 20.04 LTS x86_64
  * Compiler+version: gcc (Ubuntu 9.3.0-10ubuntu2) 9.3.0
  * Conan version: Conan version 1.26.0
  * Python version: Python 2.7.18rc1 AND Python 3.8.2

### Steps to reproduce (Include if Applicable)
`conan install opengl/system@`
`conan install xorg/system@`

### Logs (Executed commands with output) (Include/Attach if Applicable)

```
Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

Installing package: opengl/system
Requirements
    opengl/system from 'conan-center' - Cache
Packages
    opengl/system:5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9 - Cache

Installing (downloading, building) binaries...
opengl/system: ERROR: while executing system_requirements(): 'SysConfigOpenGLConan' object has no attribute 'warn'
ERROR: Error in system requirements
```


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `recipes/opengl/all/conanfile.py`
Content:
```
1 from conans import ConanFile, tools
2 from conans.errors import ConanException
3 import os
4 
5 
6 class SysConfigOpenGLConan(ConanFile):
7     name = "opengl"
8     version = "system"
9     description = "cross-platform virtual conan package for the OpenGL support"
10     topics = ("conan", "opengl", "gl")
11     url = "https://github.com/conan-io/conan-center-index"
12     homepage = "https://www.opengl.org/"
13     license = "MIT"
14     settings = ("os",)
15 
16     def package_id(self):
17         self.info.header_only()
18 
19     def _fill_cppinfo_from_pkgconfig(self, name):
20         pkg_config = tools.PkgConfig(name)
21         if not pkg_config.provides:
22             raise ConanException("OpenGL development files aren't available, give up")
23         libs = [lib[2:] for lib in pkg_config.libs_only_l]
24         lib_dirs = [lib[2:] for lib in pkg_config.libs_only_L]
25         ldflags = [flag for flag in pkg_config.libs_only_other]
26         include_dirs = [include[2:] for include in pkg_config.cflags_only_I]
27         cflags = [flag for flag in pkg_config.cflags_only_other if not flag.startswith("-D")]
28         defines = [flag[2:] for flag in pkg_config.cflags_only_other if flag.startswith("-D")]
29 
30         self.cpp_info.system_libs.extend(libs)
31         self.cpp_info.libdirs.extend(lib_dirs)
32         self.cpp_info.sharedlinkflags.extend(ldflags)
33         self.cpp_info.exelinkflags.extend(ldflags)
34         self.cpp_info.defines.extend(defines)
35         self.cpp_info.includedirs.extend(include_dirs)
36         self.cpp_info.cflags.extend(cflags)
37         self.cpp_info.cxxflags.extend(cflags)
38 
39     def system_requirements(self):
40         if tools.os_info.is_linux and self.settings.os == "Linux":
41             package_tool = tools.SystemPackageTool(conanfile=self, default_mode='verify')
42             if tools.os_info.with_yum:
43                 if tools.os_info.linux_distro == "fedora" and tools.os_info.os_version >= "32":
44                     packages = ["libglvnd-devel"]
45                 else:
46                     packages = ["mesa-libGL-devel"]
47             elif tools.os_info.with_apt:
48                 ubuntu_20_or_later = tools.os_info.linux_distro == "ubuntu" and tools.os_info.os_version >= "20"
49                 debian_11_or_later = tools.os_info.linux_distro == "debian" and tools.os_info.os_version >= "11"
50                 if ubuntu_20_or_later or debian_11_or_later:
51                     packages = ["libgl-dev"]
52                 else:
53                     packages = ["libgl1-mesa-dev"]
54             elif tools.os_info.with_pacman:
55                 packages = ["libglvnd"]
56             elif tools.os_info.with_zypper:
57                 packages = ["Mesa-libGL-devel"]
58             else:
59                 self.warn("don't know how to install OpenGL for your distro")
60             package_tool.install(update=True, packages=packages)
61 
62     def package_info(self):
63         if self.settings.os == "Macos":
64             self.cpp_info.defines.append("GL_SILENCE_DEPRECATION=1")
65             self.cpp_info.frameworks.append("OpenGL")
66         elif self.settings.os == "Windows":
67             self.cpp_info.system_libs = ["OpenGL32"]
68         elif self.settings.os == "Linux":
69             self._fill_cppinfo_from_pkgconfig('gl')
70
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/recipes/opengl/all/conanfile.py b/recipes/opengl/all/conanfile.py
--- a/recipes/opengl/all/conanfile.py
+++ b/recipes/opengl/all/conanfile.py
@@ -56,7 +56,7 @@
             elif tools.os_info.with_zypper:
                 packages = ["Mesa-libGL-devel"]
             else:
-                self.warn("don't know how to install OpenGL for your distro")
+                self.output.warn("Don't know how to install OpenGL for your distro.")
             package_tool.install(update=True, packages=packages)
 
     def package_info(self):

{"golden_diff": "diff --git a/recipes/opengl/all/conanfile.py b/recipes/opengl/all/conanfile.py\n--- a/recipes/opengl/all/conanfile.py\n+++ b/recipes/opengl/all/conanfile.py\n@@ -56,7 +56,7 @@\n             elif tools.os_info.with_zypper:\n                 packages = [\"Mesa-libGL-devel\"]\n             else:\n-                self.warn(\"don't know how to install OpenGL for your distro\")\n+                self.output.warn(\"Don't know how to install OpenGL for your distro.\")\n             package_tool.install(update=True, packages=packages)\n \n     def package_info(self):\n", "issue": "[bug] Some system packages fail to install (xorg/system, opengl/system)\n<!--\r\n  Please don't forget to update the issue title.\r\n  Include all applicable information to help us reproduce your problem.\r\n\r\n  To help us debug your issue please explain:\r\n--> When configuring a cmake project template that used conan i encountered an error while configuring cmake : \r\n`opengl/system: ERROR: while executing system_requirements(): 'SysConfigOpenGLConan' object has no attribute 'warn'`. After attemping a manual installation with `conan install opengl/system@` i still have the same problem and output. I have no idea what could be causing this and after a few hours of googling i failed to find anything that would explain this. I also get the exact same output when installing `xorg/system`\r\n\r\n### Environment Details (include every applicable attribute)\r\n  * Operating System+version: Pop!_OS 20.04 LTS x86_64\r\n  * Compiler+version: gcc (Ubuntu 9.3.0-10ubuntu2) 9.3.0\r\n  * Conan version: Conan version 1.26.0\r\n  * Python version: Python 2.7.18rc1 AND Python 3.8.2\r\n\r\n### Steps to reproduce (Include if Applicable)\r\n`conan install opengl/system@`\r\n`conan install xorg/system@`\r\n\r\n### Logs (Executed commands with output) (Include/Attach if Applicable)\r\n\r\n```\r\nConfiguration:\r\n[settings]\r\narch=x86_64\r\narch_build=x86_64\r\nbuild_type=Release\r\nos=Linux\r\nos_build=Linux\r\n[options]\r\n[build_requires]\r\n[env]\r\n\r\nInstalling package: opengl/system\r\nRequirements\r\n    opengl/system from 'conan-center' - Cache\r\nPackages\r\n    opengl/system:5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9 - Cache\r\n\r\nInstalling (downloading, building) binaries...\r\nopengl/system: ERROR: while executing system_requirements(): 'SysConfigOpenGLConan' object has no attribute 'warn'\r\nERROR: Error in system requirements\r\n```\r\n\n", "before_files": [{"content": "from conans import ConanFile, tools\nfrom conans.errors import ConanException\nimport os\n\n\nclass SysConfigOpenGLConan(ConanFile):\n    name = \"opengl\"\n    version = \"system\"\n    description = \"cross-platform virtual conan package for the OpenGL support\"\n    topics = (\"conan\", \"opengl\", \"gl\")\n    url = \"https://github.com/conan-io/conan-center-index\"\n    homepage = \"https://www.opengl.org/\"\n    license = \"MIT\"\n    settings = (\"os\",)\n\n    def package_id(self):\n        self.info.header_only()\n\n    def _fill_cppinfo_from_pkgconfig(self, name):\n        pkg_config = tools.PkgConfig(name)\n        if not pkg_config.provides:\n            raise ConanException(\"OpenGL development files aren't available, give up\")\n        libs = [lib[2:] for lib in pkg_config.libs_only_l]\n        lib_dirs = [lib[2:] for lib in pkg_config.libs_only_L]\n        ldflags = [flag for flag in pkg_config.libs_only_other]\n        include_dirs = [include[2:] for include in pkg_config.cflags_only_I]\n        cflags = [flag for flag in pkg_config.cflags_only_other if not flag.startswith(\"-D\")]\n        defines = [flag[2:] for flag in pkg_config.cflags_only_other if flag.startswith(\"-D\")]\n\n        self.cpp_info.system_libs.extend(libs)\n        self.cpp_info.libdirs.extend(lib_dirs)\n        self.cpp_info.sharedlinkflags.extend(ldflags)\n        self.cpp_info.exelinkflags.extend(ldflags)\n        self.cpp_info.defines.extend(defines)\n        self.cpp_info.includedirs.extend(include_dirs)\n        self.cpp_info.cflags.extend(cflags)\n        self.cpp_info.cxxflags.extend(cflags)\n\n    def system_requirements(self):\n        if tools.os_info.is_linux and self.settings.os == \"Linux\":\n            package_tool = tools.SystemPackageTool(conanfile=self, default_mode='verify')\n            if tools.os_info.with_yum:\n                if tools.os_info.linux_distro == \"fedora\" and tools.os_info.os_version >= \"32\":\n                    packages = [\"libglvnd-devel\"]\n                else:\n                    packages = [\"mesa-libGL-devel\"]\n            elif tools.os_info.with_apt:\n                ubuntu_20_or_later = tools.os_info.linux_distro == \"ubuntu\" and tools.os_info.os_version >= \"20\"\n                debian_11_or_later = tools.os_info.linux_distro == \"debian\" and tools.os_info.os_version >= \"11\"\n                if ubuntu_20_or_later or debian_11_or_later:\n                    packages = [\"libgl-dev\"]\n                else:\n                    packages = [\"libgl1-mesa-dev\"]\n            elif tools.os_info.with_pacman:\n                packages = [\"libglvnd\"]\n            elif tools.os_info.with_zypper:\n                packages = [\"Mesa-libGL-devel\"]\n            else:\n                self.warn(\"don't know how to install OpenGL for your distro\")\n            package_tool.install(update=True, packages=packages)\n\n    def package_info(self):\n        if self.settings.os == \"Macos\":\n            self.cpp_info.defines.append(\"GL_SILENCE_DEPRECATION=1\")\n            self.cpp_info.frameworks.append(\"OpenGL\")\n        elif self.settings.os == \"Windows\":\n            self.cpp_info.system_libs = [\"OpenGL32\"]\n        elif self.settings.os == \"Linux\":\n            self._fill_cppinfo_from_pkgconfig('gl')\n", "path": "recipes/opengl/all/conanfile.py"}], "after_files": [{"content": "from conans import ConanFile, tools\nfrom conans.errors import ConanException\nimport os\n\n\nclass SysConfigOpenGLConan(ConanFile):\n    name = \"opengl\"\n    version = \"system\"\n    description = \"cross-platform virtual conan package for the OpenGL support\"\n    topics = (\"conan\", \"opengl\", \"gl\")\n    url = \"https://github.com/conan-io/conan-center-index\"\n    homepage = \"https://www.opengl.org/\"\n    license = \"MIT\"\n    settings = (\"os\",)\n\n    def package_id(self):\n        self.info.header_only()\n\n    def _fill_cppinfo_from_pkgconfig(self, name):\n        pkg_config = tools.PkgConfig(name)\n        if not pkg_config.provides:\n            raise ConanException(\"OpenGL development files aren't available, give up\")\n        libs = [lib[2:] for lib in pkg_config.libs_only_l]\n        lib_dirs = [lib[2:] for lib in pkg_config.libs_only_L]\n        ldflags = [flag for flag in pkg_config.libs_only_other]\n        include_dirs = [include[2:] for include in pkg_config.cflags_only_I]\n        cflags = [flag for flag in pkg_config.cflags_only_other if not flag.startswith(\"-D\")]\n        defines = [flag[2:] for flag in pkg_config.cflags_only_other if flag.startswith(\"-D\")]\n\n        self.cpp_info.system_libs.extend(libs)\n        self.cpp_info.libdirs.extend(lib_dirs)\n        self.cpp_info.sharedlinkflags.extend(ldflags)\n        self.cpp_info.exelinkflags.extend(ldflags)\n        self.cpp_info.defines.extend(defines)\n        self.cpp_info.includedirs.extend(include_dirs)\n        self.cpp_info.cflags.extend(cflags)\n        self.cpp_info.cxxflags.extend(cflags)\n\n    def system_requirements(self):\n        if tools.os_info.is_linux and self.settings.os == \"Linux\":\n            package_tool = tools.SystemPackageTool(conanfile=self, default_mode='verify')\n            if tools.os_info.with_yum:\n                if tools.os_info.linux_distro == \"fedora\" and tools.os_info.os_version >= \"32\":\n                    packages = [\"libglvnd-devel\"]\n                else:\n                    packages = [\"mesa-libGL-devel\"]\n            elif tools.os_info.with_apt:\n                ubuntu_20_or_later = tools.os_info.linux_distro == \"ubuntu\" and tools.os_info.os_version >= \"20\"\n                debian_11_or_later = tools.os_info.linux_distro == \"debian\" and tools.os_info.os_version >= \"11\"\n                if ubuntu_20_or_later or debian_11_or_later:\n                    packages = [\"libgl-dev\"]\n                else:\n                    packages = [\"libgl1-mesa-dev\"]\n            elif tools.os_info.with_pacman:\n                packages = [\"libglvnd\"]\n            elif tools.os_info.with_zypper:\n                packages = [\"Mesa-libGL-devel\"]\n            else:\n                self.output.warn(\"Don't know how to install OpenGL for your distro.\")\n            package_tool.install(update=True, packages=packages)\n\n    def package_info(self):\n        if self.settings.os == \"Macos\":\n            self.cpp_info.defines.append(\"GL_SILENCE_DEPRECATION=1\")\n            self.cpp_info.frameworks.append(\"OpenGL\")\n        elif self.settings.os == \"Windows\":\n            self.cpp_info.system_libs = [\"OpenGL32\"]\n        elif self.settings.os == \"Linux\":\n            self._fill_cppinfo_from_pkgconfig('gl')\n", "path": "recipes/opengl/all/conanfile.py"}]}