0.1.3

Released on 2026-10-11.

Serc 0.1.3 expands CPython bytecode compatibility, especially for Python 3.14
optimized control flow, exception cleanup, and source locations.

Bug fixes

• Match CPython loop backedges when optimization erases final coroutine-loop
  branches, including loops inside context managers (#1031;
  #1031) (#1038;
  #1038) (#1040;
  #1040) (#1041;
  #1041) (#1042;
  #1042)
• Match CPython loop exits when optimization erases prefixes, nested-finalizer
  branches, completed manager work, or coroutine for/else arms
  (#1043; #1043)
  (#1044; #1044)
  (#1047; #1047)
  (#1054; #1054)
  (#1055; #1055)
• Preserve optimized branch exits after erased iterator work, completed managed
  branches, and discarded constants (#1188;
  #1188) (#1198;
  #1198) (#1220;
  #1220)
• Preserve loop and async-cleanup boundaries when optimization removes
  assertions or loop tails (#1102;
  #1102) (#1104;
  #1104) (#1107;
  #1107) (#1114;
  #1114)
• Preserve exits when optimization erases comprehension, context-manager,
  structured-cleanup, or finalizer work (#1106;
  #1106) (#1108;
  #1108) (#1112;
  #1112) (#1118;
  #1118)
• Preserve coroutine, loop, and finalizer exits when optimization erases
  recovery paths, assertions, or awaited alternatives (#1162;
  #1162) (#1204;
  #1204) (#1205;
  #1205) (#1207;
  #1207)
• Match CPython exception ownership when copied loop exits cross finalizers,
  backedges, or guarded handlers (#1032;
  #1032) (#1048;
  #1048) (#1052;
  #1052)
• Preserve control-flow and borrowing boundaries for nested while/else loops
  and runtime loops in finalizers (#1064;
  #1064) (#1068;
  #1068) (#1069;
  #1069) (#1078;
  #1078)
• Preserve loop and retry cleanup after recovery breaks, linear else suites,
  and nested context managers (#1080;
  #1080) (#1085;
  #1085) (#1086;
  #1086)
• Match CPython iterator-loop cleanup boundaries for chained comparisons, async
  breaks, and abrupt async else suites (#1046;
  #1046) (#1049;
  #1049) (#1088;
  #1088) (#1089;
  #1089)
• Preserve async-iterator exits into nested cleanup, outer-loop cleanup, and
  assertion cleanup (#1093;
  #1093) (#1097;
  #1097) (#1120;
  #1120) (#1127;
  #1127)
• Preserve iterator cleanup when runtime breaks, conditional loads, or guarded
  cleanup are involved (#1144;
  #1144) (#1161;
  #1161) (#1164;
  #1164)
• Preserve natural loop and iterator exits into structured, managed, nested, and
  Boolean-guarded cleanup (#1094;
  #1094) (#1095;
  #1095) (#1096;
  #1096) (#1098;
  #1098)
• Preserve coroutine-loop recovery entries and cold continuations around nested
  cleanup and async else breaks (#1131;
  #1131) (#1135;
  #1135) (#1138;
  #1138) (#1139;
  #1139)
• Preserve break paths into conditional, guarded, and awaited cleanup
  (#1137; #1137)
  (#1140; #1140)
  (#1146; #1146)
  (#1147; #1147)
• Preserve loop and managed-recovery exits through handler cleanup, context
  managers, and runtime finalizers (#1155;
  #1155) (#1187;
  #1187) (#1200;
  #1200) (#1214;
  #1214)
• Match CPython ordering for folded breaks, coroutine loop-else breaks, direct
  loop exits, and finalizer entry after loops (#1202;
  #1202) (#1203;
  #1203) (#1212;
  #1212) (#1217;
  #1217) (#1223;
  #1223)
• Preserve exception ownership when guarded finalizers and conditional
  context-manager cleanup are copied (#1035;
  #1035) (#1036;
  #1036) (#1050;
  #1050) (#1053;
  #1053)
• Preserve finalizer ownership, condition slots, and empty exits around
  terminating handlers and conditional branches (#1058;
  #1058) (#1062;
  #1062) (#1065;
  #1065) (#1066;
  #1066)
• Match CPython exception tables after erased try/else assertions and
  compacted None checks in nested context managers (#1072;
  #1072) (#1087;
  #1087)
• Preserve recovery cleanup after conditional stores, elif branches, and
  awaited branches in coroutines (#1057;
  #1057) (#1059;
  #1059) (#1063;
  #1063)
• Preserve borrowed continuations after assertion recovery in functions,
  coroutines, and context managers (#1067;
  #1067) (#1070;
  #1070) (#1073;
  #1073) (#1074;
  #1074)
• Preserve normal cleanup after terminating, guarded, reraising, or named
  exception recovery (#1071;
  #1071) (#1075;
  #1075) (#1076;
  #1076) (#1077;
  #1077)
• Preserve normal-cleanup reachability after terminal protected bodies, nested
  guards, and guarded recovery (#1081;
  #1081) (#1082;
  #1082) (#1083;
  #1083) (#1084;
  #1084)
• Preserve nested cleanup entries after guarded raises and awaited reraises
  (#1091; #1091)
  (#1092; #1092)
• Preserve cleanup after awaited try/else assertions, nested recovery
  alternatives, and asserted coroutine exits (#1099;
  #1099) (#1100;
  #1100) (#1101;
  #1101)
• Preserve cleanup reachability, boundaries, and ownership across abrupt
  branches and nested loops (#1109;
  #1109) (#1110;
  #1110) (#1111;
  #1111) (#1113;
  #1113)
• Preserve live cleanup continuations around iterator recovery, raising cleanup,
  completed handler values, and nested recovery (#1117;
  #1117) (#1119;
  #1119) (#1121;
  #1121) (#1122;
  #1122) (#1123;
  #1123)
• Preserve async-manager and coroutine cleanup entries through nested,
  returning, and guarded recovery (#1116;
  #1116) (#1124;
  #1124) (#1125;
  #1125) (#1126;
  #1126)
• Preserve cleanup joins after async-manager recovery and managed async retries
  (#1130; #1130)
  (#1133; #1133)
  (#1136; #1136)
• Preserve coroutine cleanup around raising guards and calls followed by nested
  else exits (#1141;
  #1141) (#1149;
  #1149)
• Preserve context-manager cleanup around outer iterators, conditional call
  arguments, and guarded async iterators (#1142;
  #1142) (#1143;
  #1143) (#1152;
  #1152)
• Preserve manager cleanup after awaited or conditional stores and across
  suspension (#1151; #1151)
  (#1154; #1154)
  (#1157; #1157)
  (#1168; #1168)
• Preserve normal cleanup entries and copied recovery exits around stored calls
  and raises (#1145; #1145)
  (#1148; #1148)
  (#1150; #1150)
• Preserve conditional exits and cleanup around stored reraises, guarded
  recovery, and nested repair paths (#1159;
  #1159) (#1163;
  #1163) (#1165;
  #1165)
• Preserve coroutine success and recovery paths through awaited, nested, and
  else cleanup (#1153;
  #1153) (#1156;
  #1156) (#1158;
  #1158) (#1160;
  #1160) (#1166;
  #1166)
• Preserve cleanup ownership after tuple unpacking, deletion, and comprehension
  work (#1115; #1115)
  (#1128; #1128)
  (#1132; #1132)
  (#1134; #1134)
  (#1167; #1167)
• Preserve guarded and nested recovery continuations through completed work and
  finalizers (#1185; #1185)
  (#1206; #1206)
  (#1208; #1208)
  (#1210; #1210)
• Preserve copied and coroutine recovery entries into normal and nested
  finalizers (#1211; #1211)
  (#1215; #1215)
  (#1216; #1216)
  (#1218; #1218)
• Preserve finalizer entries after completed work, context-manager cleanup, and
  raising recovery (#1221;
  #1221) (#1222;
  #1222) (#1224;
  #1224)
• Preserve cleanup joins and continuations across erased branches, awaited
  finalizers, and guarded coroutine recovery (#1193;
  #1193) (#1196;
  #1196) (#1209;
  #1209) (#1213;
  #1213)
• Preserve enclosing exception owners when returns copy nested finalizers
  (#1029; #1029)
  (#1051; #1051)
  (#1177; #1177)
  (#1181; #1181)
  (#1191; #1191)
• Preserve cleanup ownership when handler returns unwind nested finalizers and
  context managers (#1061;
  #1061) (#1178;
  #1178) (#1225;
  #1225) (#1226;
  #1226)
• End inner try regions at the CPython-compatible point before iterator and
  context-manager cleanup (#1060;
  #1060) (#1175;
  #1175) (#1180;
  #1180)
• Preserve iterator ownership and cleanup ordering through returns and
  named-handler cleanup (#1182;
  #1182) (#1183;
  #1183) (#1190;
  #1190)
• Preserve shared subscript, conditional, and tuple return paths through cleanup
  (#1033; #1033)
  (#1034; #1034)
  (#1039; #1039)
• Preserve return-copy paths after managed comprehensions and copied finalizers
  (#1179; #1179)
  (#1186; #1186)
  (#1195; #1195)
  (#1197; #1197)
• Preserve local-load borrowing boundaries when returns cross handler,
  finalizer, or branching call cleanup (#1030;
  #1030) (#1037;
  #1037) (#1045;
  #1045) (#1090;
  #1090)
• Match CPython constant folding and local-load fusion after copied exits and
  exception handlers (#1171;
  #1171) (#1174;
  #1174) (#1176;
  #1176) (#1184;
  #1184)
• Match CPython cleanup rotations and boundaries for sequence and mapping
  patterns (#1172; #1172)
  (#1173; #1173)
  (#1192; #1192)
• Preserve module cell ordering when optimization removes assertions
  (#1169; #1169)
• Preserve interrupt and monitoring checks through async-match exhaustion and
  handler cleanup (#1170;
  #1170) (#1194;
  #1194) (#1232;
  #1232)
• Match CPython bytecode for terminal conditional name stores
  (#1201; #1201)
• Preserve return source locations after removed assertions and completed
  prefixes (#1103; #1103)
  (#1228; #1228)
  (#1229; #1229)
  (#1230; #1230)
• Preserve return source locations after managed branches, erased coroutine
  assertions, and async cleanup (#1238;
  #1238) (#1239;
  #1239) (#1240;
  #1240)
• Preserve authored break lines, unlocated manager joins, and line markers
  through nested finalizers (#1079;
  #1079) (#1105;
  #1105) (#1129;
  #1129)
• Preserve original guard, exit, scope-footer, and copied-match source locations
  (#1219; #1219)
  (#1227; #1227)
  (#1233; #1233)
  (#1237; #1237)
• Avoid a debug-build assertion failure when legacy return blocks receive a late
  leading source location (#1056;
  #1056)

Other changes

• Focus the compatibility documentation on selecting and reproducing supported
  reference builds (#1244;
  #1244)