audit: handle process.Child.Term exhaustively and give useful exit information

lib/compiler/reduce.zig

@@ -291,7 +291,11 @@ fn termToInteresting(term: std.process.Child.Term) Interestingness {
             std.debug.print("interestingness check terminated with signal {t}\n", .{sig});
             return .boring;
         },
-        else => {
+        .stopped => |sig| {
+            std.debug.print("interestingness check stopped with signal {d}\n", .{sig});
+            return .boring;
+        },
+        .unknown => {
             std.debug.print("interestingness check aborted unexpectedly\n", .{});
             return .boring;
         },

lib/compiler/std-docs.zig

@@ -423,7 +423,14 @@ fn buildWasmBinary(
             );
             return error.WasmCompilationFailed;
         },
-        .stopped, .unknown => {
+        .stopped => |sig| {
+            std.log.err(
+                "the following command stopped unexpectedly with signal {d}:\n{s}",
+                .{ sig, try std.Build.Step.allocPrintCmd(arena, .inherit, null, argv.items) },
+            );
+            return error.WasmCompilationFailed;
+        },
+        .unknown => {
             std.log.err(
                 "the following command terminated unexpectedly:\n{s}",
                 .{try std.Build.Step.allocPrintCmd(arena, .inherit, null, argv.items)},

lib/std/Build/Step.zig

@@ -725,19 +725,12 @@ pub inline fn handleChildProcUnsupported(s: *Step) error{ OutOfMemory, MakeFaile
 /// Asserts that the caller has already populated `s.result_failed_command`.
 pub fn handleChildProcessTerm(s: *Step, term: std.process.Child.Term) error{ MakeFailed, OutOfMemory }!void {
     assert(s.result_failed_command != null);
-    switch (term) {
-        .exited => |code| {
-            if (code != 0) {
-                return s.fail("process exited with error code {d}", .{code});
-            }
-        },
-        .signal => |sig| {
-            return s.fail("process terminated with signal {t}", .{sig});
-        },
-        .stopped, .unknown => {
-            return s.fail("process terminated unexpectedly", .{});
-        },
-    }
+    return switch (term) {
+        .exited => |code| if (code != 0) s.fail("process exited with error code {d}", .{code}),
+        .signal => |sig| s.fail("process terminated with signal {t}", .{sig}),
+        .stopped => |sig| s.fail("process stopped with signal {d}", .{sig}),
+        .unknown => s.fail("process terminated unexpectedly", .{}),
+    };
 }
 
 pub fn allocPrintCmd(

lib/std/Build/WebServer.zig

@@ -681,7 +681,14 @@ fn buildClientWasm(ws: *WebServer, arena: Allocator, optimize: std.builtin.Optim
             );
             return error.WasmCompilationFailed;
         },
-        .stopped, .unknown => {
+        .stopped => |sig| {
+            log.err(
+                "the following command stopped unexpectedly with signal {d}:\n{s}",
+                .{ sig, try Build.Step.allocPrintCmd(arena, .inherit, null, argv.items) },
+            );
+            return error.WasmCompilationFailed;
+        },
+        .unknown => {
             log.err(
                 "the following command terminated unexpectedly:\n{s}",
                 .{try Build.Step.allocPrintCmd(arena, .inherit, null, argv.items)},

lib/std/zig/system.zig

@@ -1185,11 +1185,25 @@ fn detectAndroidApiLevel(io: Io) !u32 {
         return error.ApiLevelQueryFailed;
     };
 
-    const term = try child.wait(io);
-    if (term != .exited or term.exited != 0) {
-        std.log.err("getprop terminated abnormally: {}", .{term});
-        return error.ApiLevelQueryFailed;
+    switch (try child.wait(io)) {
+        .exited => |code| if (code != 0) {
+            std.log.err("getprop terminated abnormally with exit code: {d}", .{code});
+            return error.ApiLevelQueryFailed;
+        },
+        .signal => |sig| {
+            std.log.err("getprop terminated abnormally with signal: {t}", .{sig});
+            return error.ApiLevelQueryFailed;
+        },
+        .stopped => |sig| {
+            std.log.err("getprop stopped abnormally with signal: {d}", .{sig});
+            return error.ApiLevelQueryFailed;
+        },
+        .unknown => {
+            std.log.err("getprop terminated abnormally", .{});
+            return error.ApiLevelQueryFailed;
+        },
     }
+
     return api_level;
 }