We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Fetchmail: /var/lib/fetchmail needs persistence
According [fetchmail documentation](https://www.fetchmail.info/fetchmail-man.html#12), an `.idfile` is used to keep track of previously downloaded messages. Shouldn't that file persistent over container restarts?

I'm not a Fetchmail user, perhaps somebody can shine a light on how this currently works?

cc: @Nebukadneza, @hoellen, @kaiyou 

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `optional/fetchmail/fetchmail.py`
Content:
```
1 #!/usr/bin/python3
2 
3 import time
4 import os
5 import tempfile
6 import shlex
7 import subprocess
8 import re
9 import requests
10 import sys
11 import traceback
12 
13 
14 FETCHMAIL = """
15 fetchmail -N \
16     --sslcertck --sslcertpath /etc/ssl/certs \
17     -f {}
18 """
19 
20 
21 RC_LINE = """
22 poll "{host}" proto {protocol}  port {port}
23     user "{username}" password "{password}"
24     is "{user_email}"
25     smtphost "{smtphost}"
26     {options}
27 """
28 
29 
30 def extract_host_port(host_and_port, default_port):
31     host, _, port = re.match('^(.*?)(:([0-9]*))?$', host_and_port).groups()
32     return host, int(port) if port else default_port
33 
34 
35 def escape_rc_string(arg):
36     return "".join("\\x%2x" % ord(char) for char in arg)
37 
38 
39 def fetchmail(fetchmailrc):
40     with tempfile.NamedTemporaryFile() as handler:
41         handler.write(fetchmailrc.encode("utf8"))
42         handler.flush()
43         command = FETCHMAIL.format(shlex.quote(handler.name))
44         output = subprocess.check_output(command, shell=True)
45         return output
46 
47 
48 def run(debug):
49     try:
50         fetches = requests.get("http://" + os.environ.get("HOST_ADMIN", "admin") + "/internal/fetch").json()
51         smtphost, smtpport = extract_host_port(os.environ.get("HOST_SMTP", "smtp"), None)
52         if smtpport is None:
53             smtphostport = smtphost
54         else:
55             smtphostport = "%s/%d" % (smtphost, smtpport)
56         for fetch in fetches:
57             fetchmailrc = ""
58             options = "options antispam 501, 504, 550, 553, 554"
59             options += " ssl" if fetch["tls"] else ""
60             options += " keep" if fetch["keep"] else " fetchall"
61             fetchmailrc += RC_LINE.format(
62                 user_email=escape_rc_string(fetch["user_email"]),
63                 protocol=fetch["protocol"],
64                 host=escape_rc_string(fetch["host"]),
65                 port=fetch["port"],
66                 smtphost=smtphostport,
67                 username=escape_rc_string(fetch["username"]),
68                 password=escape_rc_string(fetch["password"]),
69                 options=options
70             )
71             if debug:
72                 print(fetchmailrc)
73             try:
74                 print(fetchmail(fetchmailrc))
75                 error_message = ""
76             except subprocess.CalledProcessError as error:
77                 error_message = error.output.decode("utf8")
78                 # No mail is not an error
79                 if not error_message.startswith("fetchmail: No mail"):
80                     print(error_message)
81                 user_info = "for %s at %s" % (fetch["user_email"], fetch["host"])
82                 # Number of messages seen is not a error as well
83                 if ("messages" in error_message and
84                         "(seen " in error_message and
85                         user_info in error_message):
86                     print(error_message)
87             finally:
88                 requests.post("http://" + os.environ.get("HOST_ADMIN", "admin") + "/internal/fetch/{}".format(fetch["id"]),
89                     json=error_message.split("\n")[0]
90                 )
91     except Exception:
92         traceback.print_exc()
93 
94 
95 if __name__ == "__main__":
96     while True:
97         time.sleep(int(os.environ.get("FETCHMAIL_DELAY", 60)))
98         run(os.environ.get("DEBUG", None) == "True")
99         sys.stdout.flush()
100
```
--- 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/optional/fetchmail/fetchmail.py b/optional/fetchmail/fetchmail.py
--- a/optional/fetchmail/fetchmail.py
+++ b/optional/fetchmail/fetchmail.py
@@ -13,6 +13,7 @@
 
 FETCHMAIL = """
 fetchmail -N \
+    --idfile /data/fetchids --uidl \
     --sslcertck --sslcertpath /etc/ssl/certs \
     -f {}
 """

{"golden_diff": "diff --git a/optional/fetchmail/fetchmail.py b/optional/fetchmail/fetchmail.py\n--- a/optional/fetchmail/fetchmail.py\n+++ b/optional/fetchmail/fetchmail.py\n@@ -13,6 +13,7 @@\n \n FETCHMAIL = \"\"\"\n fetchmail -N \\\n+    --idfile /data/fetchids --uidl \\\n     --sslcertck --sslcertpath /etc/ssl/certs \\\n     -f {}\n \"\"\"\n", "issue": "Fetchmail: /var/lib/fetchmail needs persistence\nAccording [fetchmail documentation](https://www.fetchmail.info/fetchmail-man.html#12), an `.idfile` is used to keep track of previously downloaded messages. Shouldn't that file persistent over container restarts?\r\n\r\nI'm not a Fetchmail user, perhaps somebody can shine a light on how this currently works?\r\n\r\ncc: @Nebukadneza, @hoellen, @kaiyou \n", "before_files": [{"content": "#!/usr/bin/python3\n\nimport time\nimport os\nimport tempfile\nimport shlex\nimport subprocess\nimport re\nimport requests\nimport sys\nimport traceback\n\n\nFETCHMAIL = \"\"\"\nfetchmail -N \\\n    --sslcertck --sslcertpath /etc/ssl/certs \\\n    -f {}\n\"\"\"\n\n\nRC_LINE = \"\"\"\npoll \"{host}\" proto {protocol}  port {port}\n    user \"{username}\" password \"{password}\"\n    is \"{user_email}\"\n    smtphost \"{smtphost}\"\n    {options}\n\"\"\"\n\n\ndef extract_host_port(host_and_port, default_port):\n    host, _, port = re.match('^(.*?)(:([0-9]*))?$', host_and_port).groups()\n    return host, int(port) if port else default_port\n\n\ndef escape_rc_string(arg):\n    return \"\".join(\"\\\\x%2x\" % ord(char) for char in arg)\n\n\ndef fetchmail(fetchmailrc):\n    with tempfile.NamedTemporaryFile() as handler:\n        handler.write(fetchmailrc.encode(\"utf8\"))\n        handler.flush()\n        command = FETCHMAIL.format(shlex.quote(handler.name))\n        output = subprocess.check_output(command, shell=True)\n        return output\n\n\ndef run(debug):\n    try:\n        fetches = requests.get(\"http://\" + os.environ.get(\"HOST_ADMIN\", \"admin\") + \"/internal/fetch\").json()\n        smtphost, smtpport = extract_host_port(os.environ.get(\"HOST_SMTP\", \"smtp\"), None)\n        if smtpport is None:\n            smtphostport = smtphost\n        else:\n            smtphostport = \"%s/%d\" % (smtphost, smtpport)\n        for fetch in fetches:\n            fetchmailrc = \"\"\n            options = \"options antispam 501, 504, 550, 553, 554\"\n            options += \" ssl\" if fetch[\"tls\"] else \"\"\n            options += \" keep\" if fetch[\"keep\"] else \" fetchall\"\n            fetchmailrc += RC_LINE.format(\n                user_email=escape_rc_string(fetch[\"user_email\"]),\n                protocol=fetch[\"protocol\"],\n                host=escape_rc_string(fetch[\"host\"]),\n                port=fetch[\"port\"],\n                smtphost=smtphostport,\n                username=escape_rc_string(fetch[\"username\"]),\n                password=escape_rc_string(fetch[\"password\"]),\n                options=options\n            )\n            if debug:\n                print(fetchmailrc)\n            try:\n                print(fetchmail(fetchmailrc))\n                error_message = \"\"\n            except subprocess.CalledProcessError as error:\n                error_message = error.output.decode(\"utf8\")\n                # No mail is not an error\n                if not error_message.startswith(\"fetchmail: No mail\"):\n                    print(error_message)\n                user_info = \"for %s at %s\" % (fetch[\"user_email\"], fetch[\"host\"])\n                # Number of messages seen is not a error as well\n                if (\"messages\" in error_message and\n                        \"(seen \" in error_message and\n                        user_info in error_message):\n                    print(error_message)\n            finally:\n                requests.post(\"http://\" + os.environ.get(\"HOST_ADMIN\", \"admin\") + \"/internal/fetch/{}\".format(fetch[\"id\"]),\n                    json=error_message.split(\"\\n\")[0]\n                )\n    except Exception:\n        traceback.print_exc()\n\n\nif __name__ == \"__main__\":\n    while True:\n        time.sleep(int(os.environ.get(\"FETCHMAIL_DELAY\", 60)))\n        run(os.environ.get(\"DEBUG\", None) == \"True\")\n        sys.stdout.flush()\n", "path": "optional/fetchmail/fetchmail.py"}], "after_files": [{"content": "#!/usr/bin/python3\n\nimport time\nimport os\nimport tempfile\nimport shlex\nimport subprocess\nimport re\nimport requests\nimport sys\nimport traceback\n\n\nFETCHMAIL = \"\"\"\nfetchmail -N \\\n    --idfile /data/fetchids --uidl \\\n    --sslcertck --sslcertpath /etc/ssl/certs \\\n    -f {}\n\"\"\"\n\n\nRC_LINE = \"\"\"\npoll \"{host}\" proto {protocol}  port {port}\n    user \"{username}\" password \"{password}\"\n    is \"{user_email}\"\n    smtphost \"{smtphost}\"\n    {options}\n\"\"\"\n\n\ndef extract_host_port(host_and_port, default_port):\n    host, _, port = re.match('^(.*?)(:([0-9]*))?$', host_and_port).groups()\n    return host, int(port) if port else default_port\n\n\ndef escape_rc_string(arg):\n    return \"\".join(\"\\\\x%2x\" % ord(char) for char in arg)\n\n\ndef fetchmail(fetchmailrc):\n    with tempfile.NamedTemporaryFile() as handler:\n        handler.write(fetchmailrc.encode(\"utf8\"))\n        handler.flush()\n        command = FETCHMAIL.format(shlex.quote(handler.name))\n        output = subprocess.check_output(command, shell=True)\n        return output\n\n\ndef run(debug):\n    try:\n        fetches = requests.get(\"http://\" + os.environ.get(\"HOST_ADMIN\", \"admin\") + \"/internal/fetch\").json()\n        smtphost, smtpport = extract_host_port(os.environ.get(\"HOST_SMTP\", \"smtp\"), None)\n        if smtpport is None:\n            smtphostport = smtphost\n        else:\n            smtphostport = \"%s/%d\" % (smtphost, smtpport)\n        for fetch in fetches:\n            fetchmailrc = \"\"\n            options = \"options antispam 501, 504, 550, 553, 554\"\n            options += \" ssl\" if fetch[\"tls\"] else \"\"\n            options += \" keep\" if fetch[\"keep\"] else \" fetchall\"\n            fetchmailrc += RC_LINE.format(\n                user_email=escape_rc_string(fetch[\"user_email\"]),\n                protocol=fetch[\"protocol\"],\n                host=escape_rc_string(fetch[\"host\"]),\n                port=fetch[\"port\"],\n                smtphost=smtphostport,\n                username=escape_rc_string(fetch[\"username\"]),\n                password=escape_rc_string(fetch[\"password\"]),\n                options=options\n            )\n            if debug:\n                print(fetchmailrc)\n            try:\n                print(fetchmail(fetchmailrc))\n                error_message = \"\"\n            except subprocess.CalledProcessError as error:\n                error_message = error.output.decode(\"utf8\")\n                # No mail is not an error\n                if not error_message.startswith(\"fetchmail: No mail\"):\n                    print(error_message)\n                user_info = \"for %s at %s\" % (fetch[\"user_email\"], fetch[\"host\"])\n                # Number of messages seen is not a error as well\n                if (\"messages\" in error_message and\n                        \"(seen \" in error_message and\n                        user_info in error_message):\n                    print(error_message)\n            finally:\n                requests.post(\"http://\" + os.environ.get(\"HOST_ADMIN\", \"admin\") + \"/internal/fetch/{}\".format(fetch[\"id\"]),\n                    json=error_message.split(\"\\n\")[0]\n                )\n    except Exception:\n        traceback.print_exc()\n\n\nif __name__ == \"__main__\":\n    while True:\n        time.sleep(int(os.environ.get(\"FETCHMAIL_DELAY\", 60)))\n        run(os.environ.get(\"DEBUG\", None) == \"True\")\n        sys.stdout.flush()\n", "path": "optional/fetchmail/fetchmail.py"}]}