We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Installation issue: py-jsonchema (No checksum provided for @2.6.0 requested by nrm)
The nrm package specifically requests py-jsonschema@2.6.0. Attempting to install this package results in the following error:

==> Warning: There is no checksum on file to fetch py-jsonschema@2.6.0 safely.
==> Error: Will not fetch py-jsonschema@2.6.0
Add a checksum or use --no-checksum to skip this check.


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `var/spack/repos/builtin/packages/py-jsonschema/package.py`
Content:
```
1 # Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
2 # Spack Project Developers. See the top-level COPYRIGHT file for details.
3 #
4 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
5 
6 from spack import *
7 
8 
9 class PyJsonschema(PythonPackage):
10     """Jsonschema: An(other) implementation of JSON Schema for Python."""
11 
12     homepage = "http://github.com/Julian/jsonschema"
13     url      = "https://pypi.io/packages/source/j/jsonschema/jsonschema-2.5.1.tar.gz"
14 
15     version('2.5.1', '374e848fdb69a3ce8b7e778b47c30640')
16 
17     depends_on('py-setuptools', type='build')
18     depends_on('py-vcversioner', type=('build', 'run'))
19     depends_on('py-functools32', when="^python@2.7.0:2.7.999", type=('build', 'run'))
20
```
--- 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/var/spack/repos/builtin/packages/py-jsonschema/package.py b/var/spack/repos/builtin/packages/py-jsonschema/package.py
--- a/var/spack/repos/builtin/packages/py-jsonschema/package.py
+++ b/var/spack/repos/builtin/packages/py-jsonschema/package.py
@@ -10,8 +10,9 @@
     """Jsonschema: An(other) implementation of JSON Schema for Python."""
 
     homepage = "http://github.com/Julian/jsonschema"
-    url      = "https://pypi.io/packages/source/j/jsonschema/jsonschema-2.5.1.tar.gz"
+    url      = "https://pypi.io/packages/source/j/jsonschema/jsonschema-2.6.0.tar.gz"
 
+    version('2.6.0', sha256='6ff5f3180870836cae40f06fa10419f557208175f13ad7bc26caa77beb1f6e02')
     version('2.5.1', '374e848fdb69a3ce8b7e778b47c30640')
 
     depends_on('py-setuptools', type='build')

{"golden_diff": "diff --git a/var/spack/repos/builtin/packages/py-jsonschema/package.py b/var/spack/repos/builtin/packages/py-jsonschema/package.py\n--- a/var/spack/repos/builtin/packages/py-jsonschema/package.py\n+++ b/var/spack/repos/builtin/packages/py-jsonschema/package.py\n@@ -10,8 +10,9 @@\n     \"\"\"Jsonschema: An(other) implementation of JSON Schema for Python.\"\"\"\n \n     homepage = \"http://github.com/Julian/jsonschema\"\n-    url      = \"https://pypi.io/packages/source/j/jsonschema/jsonschema-2.5.1.tar.gz\"\n+    url      = \"https://pypi.io/packages/source/j/jsonschema/jsonschema-2.6.0.tar.gz\"\n \n+    version('2.6.0', sha256='6ff5f3180870836cae40f06fa10419f557208175f13ad7bc26caa77beb1f6e02')\n     version('2.5.1', '374e848fdb69a3ce8b7e778b47c30640')\n \n     depends_on('py-setuptools', type='build')\n", "issue": "Installation issue: py-jsonchema (No checksum provided for @2.6.0 requested by nrm)\nThe nrm package specifically requests py-jsonschema@2.6.0. Attempting to install this package results in the following error:\r\n\r\n==> Warning: There is no checksum on file to fetch py-jsonschema@2.6.0 safely.\r\n==> Error: Will not fetch py-jsonschema@2.6.0\r\nAdd a checksum or use --no-checksum to skip this check.\r\n\n", "before_files": [{"content": "# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other\n# Spack Project Developers. See the top-level COPYRIGHT file for details.\n#\n# SPDX-License-Identifier: (Apache-2.0 OR MIT)\n\nfrom spack import *\n\n\nclass PyJsonschema(PythonPackage):\n    \"\"\"Jsonschema: An(other) implementation of JSON Schema for Python.\"\"\"\n\n    homepage = \"http://github.com/Julian/jsonschema\"\n    url      = \"https://pypi.io/packages/source/j/jsonschema/jsonschema-2.5.1.tar.gz\"\n\n    version('2.5.1', '374e848fdb69a3ce8b7e778b47c30640')\n\n    depends_on('py-setuptools', type='build')\n    depends_on('py-vcversioner', type=('build', 'run'))\n    depends_on('py-functools32', when=\"^python@2.7.0:2.7.999\", type=('build', 'run'))\n", "path": "var/spack/repos/builtin/packages/py-jsonschema/package.py"}], "after_files": [{"content": "# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other\n# Spack Project Developers. See the top-level COPYRIGHT file for details.\n#\n# SPDX-License-Identifier: (Apache-2.0 OR MIT)\n\nfrom spack import *\n\n\nclass PyJsonschema(PythonPackage):\n    \"\"\"Jsonschema: An(other) implementation of JSON Schema for Python.\"\"\"\n\n    homepage = \"http://github.com/Julian/jsonschema\"\n    url      = \"https://pypi.io/packages/source/j/jsonschema/jsonschema-2.6.0.tar.gz\"\n\n    version('2.6.0', sha256='6ff5f3180870836cae40f06fa10419f557208175f13ad7bc26caa77beb1f6e02')\n    version('2.5.1', '374e848fdb69a3ce8b7e778b47c30640')\n\n    depends_on('py-setuptools', type='build')\n    depends_on('py-vcversioner', type=('build', 'run'))\n    depends_on('py-functools32', when=\"^python@2.7.0:2.7.999\", type=('build', 'run'))\n", "path": "var/spack/repos/builtin/packages/py-jsonschema/package.py"}]}