diff --git a/test/elf.zig b/test/elf.zig
index 0defd9fb..b424edc9 100644
--- a/test/elf.zig
+++ b/test/elf.zig
@@ -13,6 +13,7 @@ pub fn addElfTests(b: *Build, opts: Options) *Step {
         elf_step.dependOn(testCopyrelAlignment(b, opts));
         elf_step.dependOn(testDsoIfunc(b, opts));
         elf_step.dependOn(testDsoPlt(b, opts));
+        elf_step.dependOn(testDsoUndef(b, opts));
         elf_step.dependOn(testIfuncAlias(b, opts));
         elf_step.dependOn(testIfuncDynamic(b, opts));
         elf_step.dependOn(testIfuncFuncPtr(b, opts));
@@ -164,9 +165,10 @@ fn testAsNeeded(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("NEEDED libfoo.so");
-        check.checkNext("NEEDED libbar.so");
-        check.checkNext("NEEDED libbaz.so");
+        check.checkInDynamicSection();
+        check.checkExact("NEEDED libfoo.so");
+        check.checkExact("NEEDED libbar.so");
+        check.checkExact("NEEDED libbaz.so");
         test_step.dependOn(&check.step);
     }
 
@@ -186,9 +188,11 @@ fn testAsNeeded(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("NEEDED libfoo.so");
+        check.checkInDynamicSection();
         check.checkNotPresent("NEEDED libbar.so");
-        check.checkStart("NEEDED libbaz.so");
+        check.checkInDynamicSection();
+        check.checkExact("NEEDED libfoo.so");
+        check.checkExact("NEEDED libbaz.so");
         test_step.dependOn(&check.step);
     }
 
@@ -463,9 +467,9 @@ fn testCopyrelAlignment(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("shdr {*}");
-        check.checkNext("name .copyrel");
-        check.checkNext("addralign 20");
+        check.checkStart();
+        check.checkExact("name .copyrel");
+        check.checkExact("addralign 20");
         test_step.dependOn(&check.step);
     }
 
@@ -481,9 +485,9 @@ fn testCopyrelAlignment(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("shdr {*}");
-        check.checkNext("name .copyrel");
-        check.checkNext("addralign 8");
+        check.checkStart();
+        check.checkExact("name .copyrel");
+        check.checkExact("addralign 8");
         test_step.dependOn(&check.step);
     }
 
@@ -499,9 +503,9 @@ fn testCopyrelAlignment(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("shdr {*}");
-        check.checkNext("name .copyrel");
-        check.checkNext("addralign 100");
+        check.checkStart();
+        check.checkExact("name .copyrel");
+        check.checkExact("addralign 100");
         test_step.dependOn(&check.step);
     }
 
@@ -587,6 +591,49 @@ fn testDsoPlt(b: *Build, opts: Options) *Step {
     return test_step;
 }
 
+fn testDsoUndef(b: *Build, opts: Options) *Step {
+    const test_step = b.step("test-elf-dso-undef", "");
+
+    const dso = cc(b, opts);
+    dso.addCSource(
+        \\extern int foo;
+        \\int bar = 5;
+        \\int baz() { return foo; }
+    );
+    dso.addArgs(&.{ "-shared", "-fPIC" });
+    const dso_out = dso.saveOutputAs("a.so");
+
+    const obj = cc(b, opts);
+    obj.addCSource("int foo = 3;");
+    obj.addArg("-c");
+    const obj_out = obj.saveOutputAs("b.o");
+
+    const lib = ar(b);
+    lib.addFileSource(obj_out.file);
+    const lib_out = lib.saveOutputAs("c.a");
+
+    const exe = cc(b, opts);
+    exe.addFileSource(dso_out.file);
+    exe.addPrefixedDirectorySource("-Wl,-rpath,", dso_out.dir);
+    exe.addFileSource(lib_out.file);
+    exe.addCSource(
+        \\extern int bar;
+        \\int main() {
+        \\  return bar - 5;
+        \\}
+    );
+
+    const run = exe.run();
+    test_step.dependOn(run.step());
+
+    const check = exe.check();
+    check.checkInDynamicSymtab();
+    check.checkContains("foo");
+    test_step.dependOn(&check.step);
+
+    return test_step;
+}
+
 fn testIfuncAlias(b: *Build, opts: Options) *Step {
     const test_step = b.step("test-elf-ifunc-alias", "");
 
@@ -775,11 +822,12 @@ fn testIfuncStaticPie(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("header");
-    check.checkNext("type DYN");
-    check.checkStart("shdr {*}");
-    check.checkNext("name .dynamic");
-    check.checkStart("shdr {*}");
+    check.checkStart();
+    check.checkExact("header");
+    check.checkExact("type DYN");
+    check.checkStart();
+    check.checkExact("name .dynamic");
+    check.checkStart();
     check.checkNotPresent("name .interp");
     test_step.dependOn(&check.step);
 
@@ -803,9 +851,10 @@ fn testHelloStatic(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("header");
-    check.checkNext("type EXEC");
-    check.checkStart("shdr {*}");
+    check.checkStart();
+    check.checkExact("header");
+    check.checkExact("type EXEC");
+    check.checkStart();
     check.checkNotPresent("name .dynamic");
     test_step.dependOn(&check.step);
 
@@ -824,10 +873,11 @@ fn testHelloDynamic(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("header");
-    check.checkNext("type EXEC");
-    check.checkStart("shdr {*}");
-    check.checkNext("name .dynamic");
+    check.checkStart();
+    check.checkExact("header");
+    check.checkExact("type EXEC");
+    check.checkStart();
+    check.checkExact("name .dynamic");
     test_step.dependOn(&check.step);
 
     return test_step;
@@ -845,10 +895,11 @@ fn testHelloPie(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("header");
-    check.checkNext("type DYN");
-    check.checkStart("shdr {*}");
-    check.checkNext("name .dynamic");
+    check.checkStart();
+    check.checkExact("header");
+    check.checkExact("type DYN");
+    check.checkStart();
+    check.checkExact("name .dynamic");
     test_step.dependOn(&check.step);
 
     return test_step;
diff --git a/test/macho.zig b/test/macho.zig
index 020b33b6..1e0284b1 100644
--- a/test/macho.zig
+++ b/test/macho.zig
@@ -51,7 +51,7 @@ fn testDeadStrip(b: *Build, opts: Options) *Step {
 
     const check = exe.check();
     check.checkInSymtab();
-    check.checkNotPresent("{*} (__TEXT,__text) external _iAmUnused");
+    check.checkNotPresent("(__TEXT,__text) external _iAmUnused");
     test_step.dependOn(&check.step);
 
     return test_step;
@@ -78,10 +78,12 @@ fn testDeadStripDylibs(b: *Build, opts: Options) *Step {
         exe.addArgs(&.{ "-framework", "Cocoa" });
 
         const check = exe.check();
-        check.checkStart("cmd LOAD_DYLIB");
-        check.checkNext("name {*}Cocoa");
-        check.checkStart("cmd LOAD_DYLIB");
-        check.checkNext("name {*}libobjc{*}.dylib");
+        check.checkStart();
+        check.checkExact("cmd LOAD_DYLIB");
+        check.checkContains("Cocoa");
+        check.checkStart();
+        check.checkExact("cmd LOAD_DYLIB");
+        check.checkContains("libobjc");
         test_step.dependOn(&check.step);
 
         const run = exe.run();
@@ -166,12 +168,14 @@ fn testEntryPoint(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("segname __TEXT");
-    check.checkNext("vmaddr {vmaddr}");
-    check.checkStart("cmd MAIN");
-    check.checkNext("entryoff {entryoff}");
+    check.checkStart();
+    check.checkExact("segname __TEXT");
+    check.checkExtract("vmaddr {vmaddr}");
+    check.checkStart();
+    check.checkExact("cmd MAIN");
+    check.checkExtract("entryoff {entryoff}");
     check.checkInSymtab();
-    check.checkNext("{n_value} (__TEXT,__text) external _non_main");
+    check.checkExtract("{n_value} (__TEXT,__text) external _non_main");
     check.checkComputeCompare("vmaddr entryoff +", .{ .op = .eq, .value = .{ .variable = "n_value" } });
     test_step.dependOn(&check.step);
 
@@ -222,12 +226,15 @@ fn testEntryPointDylib(b: *Build, opts: Options) *Step {
     exe.addPrefixedDirectorySource("-L", dylib.saveOutputAs("libbootstrap.dylib").dir);
 
     const check = exe.check();
-    check.checkStart("segname __TEXT");
-    check.checkNext("vmaddr {text_vmaddr}");
-    check.checkStart("sectname __stubs");
-    check.checkNext("addr {stubs_vmaddr}");
-    check.checkStart("cmd MAIN");
-    check.checkNext("entryoff {entryoff}");
+    check.checkStart();
+    check.checkExact("segname __TEXT");
+    check.checkExtract("vmaddr {text_vmaddr}");
+    check.checkStart();
+    check.checkExact("sectname __stubs");
+    check.checkExtract("addr {stubs_vmaddr}");
+    check.checkStart();
+    check.checkExact("cmd MAIN");
+    check.checkExtract("entryoff {entryoff}");
     check.checkComputeCompare("text_vmaddr entryoff +", .{
         .op = .eq,
         .value = .{ .variable = "stubs_vmaddr" }, // The entrypoint should be a synthetic stub
@@ -271,8 +278,9 @@ fn testHeaderpad(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("sectname __text");
-        check.checkNext("offset {offset}");
+        check.checkStart();
+        check.checkExact("sectname __text");
+        check.checkExtract("offset {offset}");
         switch (builtin.cpu.arch) {
             .aarch64 => check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x4000 } }),
             .x86_64 => check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x1000 } }),
@@ -291,8 +299,9 @@ fn testHeaderpad(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("sectname __text");
-        check.checkNext("offset {offset}");
+        check.checkStart();
+        check.checkExact("sectname __text");
+        check.checkExtract("offset {offset}");
         check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x10000 } });
         test_step.dependOn(&check.step);
 
@@ -308,8 +317,9 @@ fn testHeaderpad(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("sectname __text");
-        check.checkNext("offset {offset}");
+        check.checkStart();
+        check.checkExact("sectname __text");
+        check.checkExtract("offset {offset}");
         check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x10000 } });
         test_step.dependOn(&check.step);
 
@@ -325,8 +335,9 @@ fn testHeaderpad(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("sectname __text");
-        check.checkNext("offset {offset}");
+        check.checkStart();
+        check.checkExact("sectname __text");
+        check.checkExtract("offset {offset}");
         switch (builtin.cpu.arch) {
             .aarch64 => check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x4000 } }),
             .x86_64 => check.checkComputeCompare("offset", .{ .op = .gte, .value = .{ .literal = 0x1000 } }),
@@ -361,39 +372,46 @@ fn testLayout(b: *Build, opts: Options) *Step {
     exe.addHelloWorldMain();
 
     const check = exe.check();
-    check.checkStart("cmd SEGMENT_64");
-    check.checkNext("segname __LINKEDIT");
-    check.checkNext("fileoff {fileoff}");
-    check.checkNext("filesz {filesz}");
-    check.checkStart("cmd DYLD_INFO_ONLY");
-    check.checkNext("rebaseoff {rebaseoff}");
-    check.checkNext("rebasesize {rebasesize}");
-    check.checkNext("bindoff {bindoff}");
-    check.checkNext("bindsize {bindsize}");
-    check.checkNext("lazybindoff {lazybindoff}");
-    check.checkNext("lazybindsize {lazybindsize}");
-    check.checkNext("exportoff {exportoff}");
-    check.checkNext("exportsize {exportsize}");
-    check.checkStart("cmd FUNCTION_STARTS");
-    check.checkNext("dataoff {fstartoff}");
-    check.checkNext("datasize {fstartsize}");
-    check.checkStart("cmd DATA_IN_CODE");
-    check.checkNext("dataoff {diceoff}");
-    check.checkNext("datasize {dicesize}");
-    check.checkStart("cmd SYMTAB");
-    check.checkNext("symoff {symoff}");
-    check.checkNext("nsyms {symnsyms}");
-    check.checkNext("stroff {stroff}");
-    check.checkNext("strsize {strsize}");
-    check.checkStart("cmd DYSYMTAB");
-    check.checkNext("indirectsymoff {dysymoff}");
-    check.checkNext("nindirectsyms {dysymnsyms}");
+    check.checkStart();
+    check.checkExact("cmd SEGMENT_64");
+    check.checkExact("segname __LINKEDIT");
+    check.checkExtract("fileoff {fileoff}");
+    check.checkExtract("filesz {filesz}");
+    check.checkStart();
+    check.checkExact("cmd DYLD_INFO_ONLY");
+    check.checkExtract("rebaseoff {rebaseoff}");
+    check.checkExtract("rebasesize {rebasesize}");
+    check.checkExtract("bindoff {bindoff}");
+    check.checkExtract("bindsize {bindsize}");
+    check.checkExtract("lazybindoff {lazybindoff}");
+    check.checkExtract("lazybindsize {lazybindsize}");
+    check.checkExtract("exportoff {exportoff}");
+    check.checkExtract("exportsize {exportsize}");
+    check.checkStart();
+    check.checkExact("cmd FUNCTION_STARTS");
+    check.checkExtract("dataoff {fstartoff}");
+    check.checkExtract("datasize {fstartsize}");
+    check.checkStart();
+    check.checkExact("cmd DATA_IN_CODE");
+    check.checkExtract("dataoff {diceoff}");
+    check.checkExtract("datasize {dicesize}");
+    check.checkStart();
+    check.checkExact("cmd SYMTAB");
+    check.checkExtract("symoff {symoff}");
+    check.checkExtract("nsyms {symnsyms}");
+    check.checkExtract("stroff {stroff}");
+    check.checkExtract("strsize {strsize}");
+    check.checkStart();
+    check.checkExact("cmd DYSYMTAB");
+    check.checkExtract("indirectsymoff {dysymoff}");
+    check.checkExtract("nindirectsyms {dysymnsyms}");
 
     switch (builtin.cpu.arch) {
         .aarch64 => {
-            check.checkStart("cmd CODE_SIGNATURE");
-            check.checkNext("dataoff {codesigoff}");
-            check.checkNext("datasize {codesigsize}");
+            check.checkStart();
+            check.checkExact("cmd CODE_SIGNATURE");
+            check.checkExtract("dataoff {codesigoff}");
+            check.checkExtract("datasize {codesigsize}");
         },
         .x86_64 => {},
         else => unreachable,
@@ -469,8 +487,9 @@ fn testNeededFramework(b: *Build, opts: Options) *Step {
     exe.addEmptyMain();
 
     const check = exe.check();
-    check.checkStart("cmd LOAD_DYLIB");
-    check.checkNext("name {*}Cocoa");
+    check.checkStart();
+    check.checkExact("cmd LOAD_DYLIB");
+    check.checkContains("Cocoa");
     test_step.dependOn(&check.step);
 
     const run = exe.run();
@@ -494,8 +513,9 @@ fn testNeededLibrary(b: *Build, opts: Options) *Step {
     exe.addPrefixedDirectorySource("-Wl,-rpath,", dylib_out.dir);
 
     const check = exe.check();
-    check.checkStart("cmd LOAD_DYLIB");
-    check.checkNext("name {*}liba.dylib");
+    check.checkStart();
+    check.checkExact("cmd LOAD_DYLIB");
+    check.checkContains("liba.dylib");
     test_step.dependOn(&check.step);
 
     const run = exe.run();
@@ -513,12 +533,14 @@ fn testPagezeroSize(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("LC 0");
-        check.checkNext("segname __PAGEZERO");
-        check.checkNext("vmaddr 0");
-        check.checkNext("vmsize 4000");
-        check.checkStart("segname __TEXT");
-        check.checkNext("vmaddr 4000");
+        check.checkStart();
+        check.checkExact("LC 0");
+        check.checkExact("segname __PAGEZERO");
+        check.checkExact("vmaddr 0");
+        check.checkExact("vmsize 4000");
+        check.checkStart();
+        check.checkExact("segname __TEXT");
+        check.checkExact("vmaddr 4000");
         test_step.dependOn(&check.step);
     }
 
@@ -528,9 +550,10 @@ fn testPagezeroSize(b: *Build, opts: Options) *Step {
         exe.addEmptyMain();
 
         const check = exe.check();
-        check.checkStart("LC 0");
-        check.checkNext("segname __TEXT");
-        check.checkNext("vmaddr 0");
+        check.checkStart();
+        check.checkExact("LC 0");
+        check.checkExact("segname __TEXT");
+        check.checkExact("vmaddr 0");
         test_step.dependOn(&check.step);
     }
 
@@ -583,8 +606,9 @@ fn testSearchStrategy(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("cmd LOAD_DYLIB");
-        check.checkNext("name {*}liba.dylib");
+        check.checkStart();
+        check.checkExact("cmd LOAD_DYLIB");
+        check.checkContains("liba.dylib");
         test_step.dependOn(&check.step);
     }
 
@@ -601,8 +625,9 @@ fn testSearchStrategy(b: *Build, opts: Options) *Step {
         test_step.dependOn(run.step());
 
         const check = exe.check();
-        check.checkStart("cmd LOAD_DYLIB");
-        check.checkNotPresent("name {*}liba.dylib");
+        check.checkStart();
+        check.checkExact("cmd LOAD_DYLIB");
+        check.checkNotPresent("liba.dylib");
         test_step.dependOn(&check.step);
     }
 
@@ -620,8 +645,9 @@ fn testStackSize(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("cmd MAIN");
-    check.checkNext("stacksize 100000000");
+    check.checkStart();
+    check.checkExact("cmd MAIN");
+    check.checkExact("stacksize 100000000");
     test_step.dependOn(&check.step);
 
     return test_step;
@@ -820,7 +846,7 @@ fn testUnwindInfo(b: *Build, opts: Options) *Step {
 
     const check = exe.check();
     check.checkInSymtab();
-    check.checkNext("{*} external ___gxx_personality_v0");
+    check.checkContains("external ___gxx_personality_v0");
     test_step.dependOn(&check.step);
 
     return test_step;
@@ -837,8 +863,9 @@ fn testWeakFramework(b: *Build, opts: Options) *Step {
     test_step.dependOn(run.step());
 
     const check = exe.check();
-    check.checkStart("cmd LOAD_WEAK_DYLIB");
-    check.checkNext("name {*}Cocoa");
+    check.checkStart();
+    check.checkExact("cmd LOAD_WEAK_DYLIB");
+    check.checkContais("Cocoa");
     test_step.dependOn(&check.step);
 
     return test_step;
@@ -875,12 +902,13 @@ fn testWeakLibrary(b: *Build, opts: Options) *Step {
     exe.addPrefixedDirectorySource("-Wl,-rpath,", dylib_out.dir);
 
     const check = exe.check();
-    check.checkStart("cmd LOAD_WEAK_DYLIB");
-    check.checkNext("name {*}liba.dylib");
+    check.checkStart();
+    check.checkExact("cmd LOAD_WEAK_DYLIB");
+    check.checkContains("liba.dylib");
     check.checkInSymtab();
-    check.checkNext("(undefined) weak external _a (from liba)");
+    check.checkExact("(undefined) weak external _a (from liba)");
     check.checkInSymtab();
-    check.checkNext("(undefined) weak external _asStr (from liba)");
+    check.checkExact("(undefined) weak external _asStr (from liba)");
     test_step.dependOn(&check.step);
 
     const run = exe.run();