diff --git a/proj/intercept/src/intercept.c b/proj/intercept/src/intercept.c
index af73345..2964f5c 100644
--- a/proj/intercept/src/intercept.c
+++ b/proj/intercept/src/intercept.c
@@ -2355,9 +2355,9 @@ int sym(getaddrinfo)(const char *restrict node, const char *restrict service, co
     }
     const int ret = __real_getaddrinfo(node, service, hints, res);
     if (res != NULL) {
-        msg("return %i:%s; res=%qi", ret, getaddrinfoerror(ret), *res);
+        msg("return %i:%s; errno %s; res=%qi", ret, getaddrinfoerror(ret), strerrorname_np(errno), *res);
     } else {
-        msg("return %i:%s", ret, getaddrinfoerror(ret));
+        msg("return %i:%s; errno %s", ret, getaddrinfoerror(ret), strerrorname_np(errno));
     }
     return ret;
 }
diff --git a/proj/server/src/intercept/__init__.py b/proj/server/src/intercept/__init__.py
index 007672a..eadb6d2 100644
--- a/proj/server/src/intercept/__init__.py
+++ b/proj/server/src/intercept/__init__.py
@@ -109,9 +109,9 @@ class Handler(StreamRequestHandler):
     def parse_arg(argument: str) -> tuple[any, int]:
         if argument == '':
             return None, 0
-        m = re.match(r'^\s*(\(nil\)|NULL|null|nullptr)\s*(,|$)', argument)
+        m = re.match(r'^\s*(\(nil\)|NULL|null|nullptr)\s*(,|]|}|$)', argument)
         if m:
-            return 0, len(m.group(0))
+            return 0, len(m.group(0)) - (1 if m.group(2) in ('}', ']') else 0)
         m = re.match(r'\s*"', argument)
         if m:
             idx = len(m.group(0)) - 1
@@ -120,17 +120,37 @@ class Handler(StreamRequestHandler):
             if idx < len(argument) and argument[idx] == ',':
                 idx += 1
             return s, idx
-        m = re.match(r'^\s*(.*?)([,:]|$)', argument)
+        m = re.match(r'\s*\[', argument)
+        if m:
+            idx = len(m.group(0))
+            s, i = Handler.parse_args(argument[idx:])
+            idx += i
+            if idx < len(argument) and argument[idx] == ',':
+                idx += 1
+            return s, idx
+        m = re.match(r'\s*\{', argument)
+        if m:
+            idx = len(m.group(0))
+            s, i = Handler.parse_args(argument[idx:], named=True)
+            idx += i
+            if idx < len(argument) and argument[idx] == ',':
+                idx += 1
+            return s, idx
+        m = re.match(r'^\s*(.*?)([,:\]}]|$)', argument)
         a, e = m.group(1), m.group(2)
         idx = len(m.group(0))
         if a.startswith('0x'):
             val = int(a[2:], 16)
         elif a.startswith('0') and len(a) > 1:
             val = int(a[1:], 8)
+        elif a in ('(nil)', 'NULL', 'null', 'nullptr'):
+            val = 0
         else:
             val = int(a, 10)
         if e in (',', ''):
             return val, idx
+        elif e in ('}', ']'):
+            return val, idx - 1
         if argument[idx] == '[':
             idx += 1
             l, i = Handler.parse_args(argument[idx:])
@@ -155,18 +175,12 @@ class Handler(StreamRequestHandler):
                 idx += 1
             return (val, s), idx
         elif argument[idx] == '{':
-            m = re.match(r'^[^}]*}', argument[idx:])
-            if not m or not m.group(0).startswith('{') or not m.group(0).endswith('}'):
-                raise ValueError()
-            value = m.group(0)
-            idx += len(value)
+            idx += 1
+            l, i = Handler.parse_args(argument[idx:], named=True)
+            idx += i
             if idx < len(argument) and argument[idx] == ',':
                 idx += 1
-            entries = {}
-            for e in [v.strip() for v in value[1:-1].split(',') if len(v.strip()) > 0]:
-                k, v = e.split(':', 1)
-                entries[k.strip()] = Handler.parse_arg(v)[0]
-            return (val, entries), idx
+            return (val, list(l)), idx
         else:
             m = re.match(r'[A-Z0-9_]+', argument[idx:])
             if not m:
@@ -178,17 +192,27 @@ class Handler(StreamRequestHandler):
             return (val, value), idx
 
     @staticmethod
-    def parse_args(arguments: str) -> tuple[tuple, int]:
-        args = []
+    def parse_args(arguments: str, named: bool = False) -> tuple[tuple or dict, int]:
+        # FIXME parse dicts in lists, dicts in dicts, ...
+        print(named, arguments)
+        args = [] if not named else {}
         idx = 0
+        name = None
         while idx < len(arguments):
-            if arguments[idx] == ']':
+            if arguments[idx] == ']' and not named or arguments[idx] == '}' and named:
                 idx += 1
                 break
+            elif named:
+                m = re.match(r'^\s*([^:]+):', arguments[idx:])
+                idx += len(m.group(0))
+                name = m.group(1)
             val, i = Handler.parse_arg(arguments[idx:])
-            args.append(val)
+            if named:
+                args[name] = val
+            else:
+                args.append(val)
             idx += i
-        return tuple(args), idx
+        return tuple(args) if not named else args, idx
 
     def handle_msg(self, msg: bytes):
         timestamp, pid, tid, data = msg.rstrip(b'\n').split(b' ', 3)
diff --git a/proj/server/src/test-interrupts b/proj/server/src/test-interrupts
index 7be8d01..72cea09 100755
--- a/proj/server/src/test-interrupts
+++ b/proj/server/src/test-interrupts
@@ -26,7 +26,7 @@ def main() -> None:
         'INTERCEPT': 'unix:' + socket_name,
         'INTERCEPT_VERBOSE': '1',
         'INTERCEPT_FUNCTIONS': '*',
-        'INTERCEPT_LIBRARIES': '*,-/lib*,-/usr/lib*',
+        'INTERCEPT_LIBRARIES': ','.join(['*', '-/lib*', '-/usr/lib*']),
     })
 
 
diff --git a/proj/server/src/test-memory b/proj/server/src/test-memory
index 893a5ad..5f8a3a4 100755
--- a/proj/server/src/test-memory
+++ b/proj/server/src/test-memory
@@ -26,7 +26,7 @@ def main() -> None:
         'INTERCEPT': 'unix:' + socket_name,
         'INTERCEPT_VERBOSE': '1',
         'INTERCEPT_FUNCTIONS': ','.join(['malloc', 'calloc', 'realloc', 'reallocarray', 'free', 'getaddrinfo', 'freeaddrinfo']),
-        'INTERCEPT_LIBRARIES': '*,-/lib*,-/usr/lib*',
+        'INTERCEPT_LIBRARIES': ','.join(['*', '-/lib*', '-/usr/lib*']),
     })
 
 
diff --git a/proj/server/src/test-return-values b/proj/server/src/test-return-values
index 6dfbe60..a051ce2 100755
--- a/proj/server/src/test-return-values
+++ b/proj/server/src/test-return-values
@@ -37,7 +37,7 @@ def main() -> None:
             'INTERCEPT': 'unix:' + socket_name,
             'INTERCEPT_VERBOSE': '1',
             'INTERCEPT_FUNCTIONS': '*',
-            'INTERCEPT_LIBRARIES': '*,-/lib*,-/usr/lib*',
+            'INTERCEPT_LIBRARIES': ','.join(['*', '-/lib*', '-/usr/lib*']),
         })
     for i, name in enumerate(ctx['call_sequence']):
         errors = [r[1] for r in ctx['results'] if r[0] == i]