Lighttpd

I was trying to set up a customized vhost system using mod_magnet and lua, but I couldn't get it to work. To troubleshoot my issue, I decided to try the basic mod_simple_vhost code from the ModMagnetExamples page, but that seems to fail with the exact same error. Here's the error log of the request I'm making:

2023-07-14 14:46:51: (../src/h1.c.497) fd:10 rqst: GET /post/ HTTP/1.1
2023-07-14 14:46:51: (../src/h1.c.497) fd:10 rqst: Host: localhost:8000
2023-07-14 14:46:51: (../src/h1.c.497) fd:10 rqst: User-Agent: curl/8.1.2
2023-07-14 14:46:51: (../src/h1.c.497) fd:10 rqst: Accept: */*
2023-07-14 14:46:51: (../src/h1.c.497) fd:10 rqst: 
2023-07-14 14:46:51: (../src/response.c.260) -- parsed Request-URI
2023-07-14 14:46:51: (../src/response.c.262) Request-URI     : /post/
2023-07-14 14:46:51: (../src/response.c.264) URI-scheme      : http
2023-07-14 14:46:51: (../src/response.c.266) URI-authority   : localhost:8000
2023-07-14 14:46:51: (../src/response.c.268) URI-path (clean): /post/
2023-07-14 14:46:51: (../src/response.c.270) URI-query       : 
2023-07-14 14:46:51: (../src/mod_magnet.c.3245) lua: [string "/opt/lighttpd_experiment/handlers/simple..."]:18: couldn't store 'physical.doc_root' in r.req_attr[]
2023-07-14 14:46:51: (../src/mod_magnet.c.3245) lua: stack traceback:
2023-07-14 14:46:51: (../src/mod_magnet.c.3245) lua: \t[C]: in metamethod 'newindex'
2023-07-14 14:46:51: (../src/mod_magnet.c.3245) lua: \t[string "/opt/lighttpd_experiment/handlers/simple..."]:18: in main chunk
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: HTTP/1.1 500 Internal Server Error
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: Content-Type: text/html
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: Content-Length: 365
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: Date: Fri, 14 Jul 2023 12:46:51 GMT
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: Server: lighttpd/1.4.71
2023-07-14 14:46:51: (../src/h1.c.248) fd:10 resp: 

And here's is the entire config file I'm using. As you can see, the simple_vhost script is the first of several lua scripts to run on the attract-raw-url-to phase, but apart from that nothing particularly special is going on.

# {{{ variables
var.basedir = env.LIGHTTPD_BASEDIR
var.magnetdir = var.basedir + "/handlers" 
var.statedir = var.basedir + "/state" 
var.logdir = var.statedir + "/log" 
# }}}

# {{{ modules
# At the very least, mod_access and mod_accesslog should be enabled.
# All other modules should only be loaded if necessary.
# NOTE: the order of modules is important.
server.modules = (
    "mod_rewrite",
#    "mod_redirect",
#    "mod_alias",
    "mod_access",
#    "mod_auth",
#    "mod_status",
#    "mod_setenv",
#    "mod_proxy",
#    "mod_simple_vhost",
#    "mod_evhost",
#    "mod_userdir",
#    "mod_deflate",
#    "mod_ssi",
#    "mod_expire",
#    "mod_rrdtool",
#    "mod_webdav",
    "mod_accesslog",
    "mod_magnet" 
)
# }}}

# {{{ includes
include "mimetypes.conf" 
# }}}

# {{{ server settings
#server.username      = "lighttpd" 
#server.groupname     = "lighttpd" 

server.port = env.LIGHTTPD_PORT

server.document-root = "/dev/null" 
server.pid-file      = var.statedir + "/lighttpd.pid" 

server.errorlog      = var.logdir + "/error.log" 

# error-handler for status 404
# server.error-handler-404 = "/error-handler.html" 
# server.error-handler-404 = "/error-handler.php" 

# Format: <errorfile-prefix><status-code>.html
# -> ..../status-404.html for 'File not found'
# server.errorfile-prefix    = var.basedir + "/error/status-" 

index-file.names     = ("index.html")

# {{{ mod_staticfile

# which extensions should not be handled via static-file transfer
# (extensions that are usually handled by mod_cgi, mod_fastcgi, etc).
static-file.exclude-extensions = (".php", ".pl", ".cgi", ".fcgi")
# }}}

# {{{ mod_accesslog
accesslog.filename   = var.logdir + "/access.log" 
# }}}

# {{{ mod_access
# see access.txt
url.access-deny = ("~", ".inc")
# }}}

# {{{ extra rules

magnet.attract-raw-url-to = (
    var.magnetdir + "/simple_vhost.lua",
    var.magnetdir + "/activity.lua" 
)

# Handle Webfinger requests
$HTTP["url"] == "/.well-known/webfinger" {
    magnet.attract-raw-url-to = (var.magnetdir + "/webfinger.lua")
}

# Handle posts to inbox
$HTTP["url"] == "/inbox" {
    $HTTP["request-method"] == "POST" {
        magnet.attract-raw-url-to = (var.magnetdir + "/inbox.lua")
    }
}

# }}}

# {{{ debug
debug.log-request-header   = "enable" 
debug.log-response-header  = "enable" 
debug.log-request-handling = "enable" 
debug.log-file-not-found   = "enable" 
# }}}