cmd/internal/fuzztest: TestScript/test_fuzz_test_race failures

[gopherbot]

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T08:28:57Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race3556886075/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x28837c3341e0 m=4 mp=0x28837c37d008 [running]:
        panic({0x10a80358?, 0x28837cd771a0?})
        	runtime/panic.go:879 +0x16f fp=0x28837cf5b478 sp=0x28837cf5b3c8 pc=0x1058224f
        runtime.panicBounds64(0x1070cb6f, 0x28837cf5b4e8)
        	runtime/panic.go:236 +0xf7 fp=0x28837cf5b4d8 sp=0x28837cf5b478 pc=0x105494b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x28837cf5b578 sp=0x28837cf5b4d8 pc=0x1058a028
        cmd/link/internal/ld.(*Link).domacho(0x28837c32e600)
...
        runtime.gcBgMarkWorker(0x28837c3541c0)
        	runtime/mgc.go:1773 +0xeb fp=0x28837c3747c8 sp=0x28837c374740 pc=0x1052b44b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x28837c3747e0 sp=0x28837c3747c8 pc=0x1052b337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x28837c3747e8 sp=0x28837c3747e0 pc=0x10589bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (178.05s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-03-11 05:58 gotip-darwin-amd64-longtest go@d3651c58 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T08:28:57Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race3556886075/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x28837c3341e0 m=4 mp=0x28837c37d008 [running]:
        panic({0x10a80358?, 0x28837cd771a0?})
        	runtime/panic.go:879 +0x16f fp=0x28837cf5b478 sp=0x28837cf5b3c8 pc=0x1058224f
        runtime.panicBounds64(0x1070cb6f, 0x28837cf5b4e8)
        	runtime/panic.go:236 +0xf7 fp=0x28837cf5b4d8 sp=0x28837cf5b478 pc=0x105494b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x28837cf5b578 sp=0x28837cf5b4d8 pc=0x1058a028
        cmd/link/internal/ld.(*Link).domacho(0x28837c32e600)
...
        runtime.gcBgMarkWorker(0x28837c3541c0)
        	runtime/mgc.go:1773 +0xeb fp=0x28837c3747c8 sp=0x28837c374740 pc=0x1052b44b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x28837c3747e0 sp=0x28837c3747c8 pc=0x1052b337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x28837c3747e8 sp=0x28837c3747e0 pc=0x10589bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (178.05s)

2026-03-11 05:58 gotip-darwin-amd64-longtest go@e30e65f7 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T07:11:21Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race569237617/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0xe750b1d21e0 m=4 mp=0xe750b21b008 [running]:
        panic({0xc127358?, 0xe750b1e89f0?})
        	runtime/panic.go:879 +0x16f fp=0xe750b935478 sp=0xe750b9353c8 pc=0xbc2924f
        runtime.panicBounds64(0xbdb3b6f, 0xe750b9354e8)
        	runtime/panic.go:236 +0xf7 fp=0xe750b9354d8 sp=0xe750b935478 pc=0xbbf04b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0xe750b935578 sp=0xe750b9354d8 pc=0xbc31028
        cmd/link/internal/ld.(*Link).domacho(0xe750b1cc600)
...
        runtime.gcBgMarkWorker(0xe750b1f21c0)
        	runtime/mgc.go:1773 +0xeb fp=0xe750b2127c8 sp=0xe750b212740 pc=0xbbd244b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0xe750b2127e0 sp=0xe750b2127c8 pc=0xbbd2337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0xe750b2127e8 sp=0xe750b2127e0 pc=0xbc30bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (174.59s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-03-11 03:51 gotip-darwin-amd64-longtest go@45c6fb4b cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T10:01:30Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race503997537/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x33d1020841e0 m=0 mp=0x27150e0 [running]:
        panic({0x26bf358?, 0x33d1021ad1d0?})
        	runtime/panic.go:879 +0x16f fp=0x33d102d75478 sp=0x33d102d753c8 pc=0x21c124f
        runtime.panicBounds64(0x234bb6f, 0x33d102d754e8)
        	runtime/panic.go:236 +0xf7 fp=0x33d102d754d8 sp=0x33d102d75478 pc=0x21884b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x33d102d75578 sp=0x33d102d754d8 pc=0x21c9028
        cmd/link/internal/ld.(*Link).domacho(0x33d1021e2400)
...
        runtime.gcBgMarkWorker(0x33d10218c150)
        	runtime/mgc.go:1773 +0xeb fp=0x33d1021887c8 sp=0x33d102188740 pc=0x216a44b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x33d1021887e0 sp=0x33d1021887c8 pc=0x216a337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x33d1021887e8 sp=0x33d1021887e0 pc=0x21c8bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (167.90s)

2026-03-11 04:05 gotip-darwin-amd64-longtest go@97d64304 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T05:38:31Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race2120943797/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x218aee1141e0 m=2 mp=0x218aee15c808 [running]:
        panic({0xcffe358?, 0x218aee12a888?})
        	runtime/panic.go:879 +0x16f fp=0x218aee1f3478 sp=0x218aee1f33c8 pc=0xcb0024f
        runtime.panicBounds64(0xcc8ab6f, 0x218aee1f34e8)
        	runtime/panic.go:236 +0xf7 fp=0x218aee1f34d8 sp=0x218aee1f3478 pc=0xcac74b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x218aee1f3578 sp=0x218aee1f34d8 pc=0xcb08028
        cmd/link/internal/ld.(*Link).domacho(0x218aee264400)
...
        runtime.gcBgMarkWorker(0x218aee20c150)
        	runtime/mgc.go:1773 +0xeb fp=0x218aee2087c8 sp=0x218aee208740 pc=0xcaa944b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x218aee2087e0 sp=0x218aee2087c8 pc=0xcaa9337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x218aee2087e8 sp=0x218aee2087e0 pc=0xcb07bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (172.80s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-03-11 03:49 gotip-darwin-amd64-longtest go@59b188ce cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T11:06:09Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race2445169671/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x2d15fb90a1e0 m=3 mp=0x2d15fb980008 [running]:
        panic({0x8d2b358?, 0x2d15fc104c48?})
        	runtime/panic.go:879 +0x16f fp=0x2d15fba31478 sp=0x2d15fba313c8 pc=0x882d24f
        runtime.panicBounds64(0x89b7b6f, 0x2d15fba314e8)
        	runtime/panic.go:236 +0xf7 fp=0x2d15fba314d8 sp=0x2d15fba31478 pc=0x87f44b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x2d15fba31578 sp=0x2d15fba314d8 pc=0x8835028
        cmd/link/internal/ld.(*Link).domacho(0x2d15fb904600)
...
        runtime.gcBgMarkWorker(0x2d15fb92a1c0)
        	runtime/mgc.go:1773 +0xeb fp=0x2d15fb94a7c8 sp=0x2d15fb94a740 pc=0x87d644b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x2d15fb94a7e0 sp=0x2d15fb94a7c8 pc=0x87d6337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x2d15fb94a7e8 sp=0x2d15fb94a7e0 pc=0x8834bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (123.90s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-03-11 03:18 gotip-darwin-amd64-longtest go@23fde5c4 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T12:24:29Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race3317574044/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x16d6ab6841e0 m=3 mp=0x16d6ab6cd008 [running]:
        panic({0x88ff358?, 0x16d6abea9380?})
        	runtime/panic.go:879 +0x16f fp=0x16d6ab7e9478 sp=0x16d6ab7e93c8 pc=0x840124f
        runtime.panicBounds64(0x858bb6f, 0x16d6ab7e94e8)
        	runtime/panic.go:236 +0xf7 fp=0x16d6ab7e94d8 sp=0x16d6ab7e9478 pc=0x83c84b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x16d6ab7e9578 sp=0x16d6ab7e94d8 pc=0x8409028
        cmd/link/internal/ld.(*Link).domacho(0x16d6ab7e4400)
...
        runtime.gcBgMarkWorker(0x16d6ab78e150)
        	runtime/mgc.go:1773 +0xeb fp=0x16d6ab6cafc8 sp=0x16d6ab6caf40 pc=0x83aa44b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x16d6ab6cafe0 sp=0x16d6ab6cafc8 pc=0x83aa337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x16d6ab6cafe8 sp=0x16d6ab6cafe0 pc=0x8408bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (157.95s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-03-11 17:12 gotip-darwin-amd64-longtest go@96d6d388 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-03-11T19:30:03Z
    run.go:252: $WORK=/Volumes/Work/s/w/ir/x/t/TestScripttest_fuzz_test_race3052414200/001
    run.go:259: 
        BOTO_CONFIG=/Volumes/Work/s/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Volumes/Work/s/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        panic: runtime error: index out of range [2] with length 2
        
        goroutine 1 gp=0x3e718ea141e0 m=7 mp=0x3e718f000008 [running]:
        panic({0xc818358?, 0x3e718effed80?})
        	runtime/panic.go:879 +0x16f fp=0x3e718eadf478 sp=0x3e718eadf3c8 pc=0xc31a24f
        runtime.panicBounds64(0xc4a4b6f, 0x3e718eadf4e8)
        	runtime/panic.go:236 +0xf7 fp=0x3e718eadf4d8 sp=0x3e718eadf478 pc=0xc2e14b7
        runtime.panicBounds()
        	runtime/asm_amd64.s:2132 +0x68 fp=0x3e718eadf578 sp=0x3e718eadf4d8 pc=0xc322028
        cmd/link/internal/ld.(*Link).domacho(0x3e718ea0e400)
...
        runtime.gcBgMarkWorker(0x3e718ea9e310)
        	runtime/mgc.go:1773 +0xeb fp=0x3e718ebf47c8 sp=0x3e718ebf4740 pc=0xc2c344b
        runtime.gcBgMarkStartWorkers.gowrap1()
        	runtime/mgc.go:1677 +0x17 fp=0x3e718ebf47e0 sp=0x3e718ebf47c8 pc=0xc2c3337
        runtime.goexit({})
        	runtime/asm_amd64.s:1774 +0x1 fp=0x3e718ebf47e8 sp=0x3e718ebf47e0 pc=0xc321bc1
        created by runtime.gcBgMarkStartWorkers in goroutine 1
        	runtime/mgc.go:1677 +0x105
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (183.84s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/fuzztest" && test == "TestScript/test_fuzz_test_race"

2026-04-15 17:55 gotip-darwin-amd64-longtest go@e73621e3 cmd/internal/fuzztest.TestScript/test_fuzz_test_race (log)

=== RUN   TestScript/test_fuzz_test_race
=== PAUSE TestScript/test_fuzz_test_race
=== CONT  TestScript/test_fuzz_test_race
    run.go:250: 2026-04-16T11:55:47Z
    run.go:252: $WORK=/Users/swarming/.swarming/w/ir/x/t/TestScripttest_fuzz_test_race1146223451/001
    run.go:259: 
        BOTO_CONFIG=/Users/swarming/.swarming/w/ir/x/a/gsutil-bbagent/.boto
        CIPD_ARCHITECTURE=amd64
        CIPD_CACHE_DIR=/Users/swarming/.swarming/w/ir/cache/cipd_cache
        CIPD_PROTOCOL=v2
...
        ../../TestScript3450817067/001/testgoroot/src/runtime/malloc_generated.go:6204:18: internal compiler error: missing Types entry: ! ���$>����� && (constsize < c.tinyoffset || c.tiny == 0)
        
        goroutine 1 [running]:
        runtime/debug.Stack()
        	runtime/debug/stack.go:26 +0x5e
        cmd/compile/internal/base.FatalfAt({0xbdb38108?, 0x3e24?}, {0xc076229, 0x17}, {0x3e24bcafeef8, 0x1, 0x1})
        	cmd/compile/internal/base/print.go:232 +0x18b
        cmd/compile/internal/noder.(*pkgWriter).fatalf(0x3e24be938340?, {0xc9f81d0?, 0x3e24bb40fb00?}, {0xc076229, 0x17}, {0x3e24bcafeef8, 0x1, 0x1})
        	cmd/compile/internal/noder/writer.go:134 +0x5c
        cmd/compile/internal/noder.(*pkgWriter).typeAndValue(0x3e24bdb38000, {0xc9fb030, 0x3e24bb40fb00})
...
        	cmd/compile/internal/noder/unified.go:198 +0xb6
        cmd/compile/internal/noder.LoadPackage({0x3e24b97cfca8, 0xb5, 0xbd})
        	cmd/compile/internal/noder/noder.go:76 +0x509
        cmd/compile/internal/gc.Main(0xc9ff628)
        	cmd/compile/internal/gc/main.go:217 +0xcd2
        main.main()
        	cmd/compile/main.go:57 +0xf9
        
    run.go:259: FAIL: testdata/script/test_fuzz_test_race.txt:12: go test -fuzz=xxx -race -v: exit status 1
--- FAIL: TestScript/test_fuzz_test_race (20.75s)

— watchflakes