[INFO] updating cached repository https://github.com/ftabaro/mutation-viewer
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9db01032796d52d9cc56e115b26a234fefce2b0e
[INFO] testing ftabaro/mutation-viewer against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fftabaro%2Fmutation-viewer" "work/builds/worker-7/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ftabaro/mutation-viewer on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/ftabaro/mutation-viewer
[INFO] finished tweaking git repo https://github.com/ftabaro/mutation-viewer
[INFO] tweaked toml for git repo https://github.com/ftabaro/mutation-viewer written to work/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/ftabaro/mutation-viewer already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 8ce07aae3c164a46e0bca7807445ca1ebc0eba77cfb395200b5246c47e498896
[INFO] running `"docker" "start" "-a" "8ce07aae3c164a46e0bca7807445ca1ebc0eba77cfb395200b5246c47e498896"`
[INFO] [stderr]    Compiling version_check v0.1.3
[INFO] [stderr]    Compiling libc v0.2.36
[INFO] [stderr]    Compiling cfg-if v0.1.2
[INFO] [stderr]    Compiling num-traits v0.2.0
[INFO] [stderr]    Compiling cc v1.0.4
[INFO] [stderr]    Compiling gcc v0.3.54
[INFO] [stderr]    Compiling matches v0.1.6
[INFO] [stderr]    Compiling encoding_index_tests v0.1.4
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling lazy_static v1.0.0
[INFO] [stderr]    Compiling safemem v0.1.1
[INFO] [stderr]    Compiling unicode-normalization v0.1.5
[INFO] [stderr]    Compiling safemem v0.2.0
[INFO] [stderr]    Compiling serde v1.0.27
[INFO] [stderr]    Compiling ascii v0.7.1
[INFO] [stderr]    Compiling dtoa v0.4.2
[INFO] [stderr]    Compiling httparse v1.2.4
[INFO] [stderr]    Compiling utf8-ranges v1.0.0
[INFO] [stderr]    Compiling regex-syntax v0.4.2
[INFO] [stderr]    Compiling chunked_transfer v0.3.1
[INFO] [stderr]    Compiling byteorder v1.2.1
[INFO] [stderr]    Compiling itoa v0.3.4
[INFO] [stderr]    Compiling strsim v0.6.0
[INFO] [stderr]    Compiling sha1 v0.2.0
[INFO] [stderr]    Compiling log v0.4.1
[INFO] [stderr]    Compiling unicode-bidi v0.3.4
[INFO] [stderr]    Compiling encoding-index-japanese v1.20141219.5
[INFO] [stderr]    Compiling encoding-index-simpchinese v1.20141219.5
[INFO] [stderr]    Compiling encoding-index-singlebyte v1.20141219.5
[INFO] [stderr]    Compiling encoding-index-korean v1.20141219.5
[INFO] [stderr]    Compiling encoding-index-tradchinese v1.20141219.5
[INFO] [stderr]    Compiling unreachable v1.0.0
[INFO] [stderr]    Compiling base64 v0.7.0
[INFO] [stderr]    Compiling log v0.3.9
[INFO] [stderr]    Compiling rand v0.4.2
[INFO] [stderr]    Compiling time v0.1.39
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling memchr v2.0.1
[INFO] [stderr]    Compiling num_cpus v1.8.0
[INFO] [stderr]    Compiling filetime v0.1.15
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling serde_derive_internals v0.19.0
[INFO] [stderr]    Compiling num-integer v0.1.36
[INFO] [stderr]    Compiling num-traits v0.1.43
[INFO] [stderr]    Compiling thread_local v0.3.5
[INFO] [stderr]    Compiling idna v0.1.4
[INFO] [stderr]    Compiling mime v0.2.6
[INFO] [stderr]    Compiling buf_redux v0.6.1
[INFO] [stderr]    Compiling remove_dir_all v0.3.0
[INFO] [stderr]    Compiling term v0.2.14
[INFO] [stderr]    Compiling twoway v0.1.7
[INFO] [stderr]    Compiling aho-corasick v0.6.4
[INFO] [stderr]    Compiling threadpool v1.7.1
[INFO] [stderr]    Compiling encoding v0.2.33
[INFO] [stderr]    Compiling num-iter v0.1.35
[INFO] [stderr]    Compiling num v0.1.41
[INFO] [stderr]    Compiling rand v0.3.22
[INFO] [stderr]    Compiling tempdir v0.3.6
[INFO] [stderr]    Compiling regex v0.2.5
[INFO] [stderr]    Compiling chrono v0.2.25
[INFO] [stderr]    Compiling chrono v0.4.0
[INFO] [stderr]    Compiling uuid v0.1.18
[INFO] [stderr]    Compiling phf_shared v0.7.21
[INFO] [stderr]    Compiling brotli-sys v0.2.1
[INFO] [stderr]    Compiling miniz-sys v0.1.10
[INFO] [stderr]    Compiling phf_generator v0.7.21
[INFO] [stderr]    Compiling phf v0.7.21
[INFO] [stderr]    Compiling url v1.6.0
[INFO] [stderr]    Compiling url v0.2.38
[INFO] [stderr]    Compiling phf_codegen v0.7.21
[INFO] [stderr]    Compiling mime_guess v1.8.3
[INFO] [stderr]    Compiling serde_derive v1.0.27
[INFO] [stderr]    Compiling flate2 v0.2.20
[INFO] [stderr] warning[E0713]: borrow may still be in use when destructor runs
[INFO] [stderr]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/url-1.6.0/src/form_urlencoded.rs:261:40
[INFO] [stderr]     |
[INFO] [stderr] 259 | impl<'a> Target for ::UrlQuery<'a> {
[INFO] [stderr]     |      -- lifetime `'a` defined here
[INFO] [stderr] 260 |     fn as_mut_string(&mut self) -> &mut String { &mut self.url.serialization }
[INFO] [stderr] 261 |     fn finish(self) -> &'a mut ::Url { self.url }
[INFO] [stderr]     |                                        ^^^^^^^^ - here, drop of `self` needs exclusive access to `*self.url`, because the type `UrlQuery<'_>` implements the `Drop` trait
[INFO] [stderr]     |                                        |
[INFO] [stderr]     |                                        returning this value requires that `*self.url` is borrowed for `'a`
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]     = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]    Compiling flate2 v1.0.1
[INFO] [stderr]    Compiling tiny_http v0.5.9
[INFO] [stderr] error: failed to run custom build command for `mime_guess v1.8.3`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/mime_guess-4137e18e6f2d2210/build-script-gen_mime_types` (exit code: 101)
[INFO] [stderr] --- stderr
[INFO] [stderr] thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 30, kind: Other, message: "Read-only file system" }', src/libcore/result.rs:1084:5
[INFO] [stderr] stack backtrace:
[INFO] [stderr]    0:     0x5631a07e95ab - backtrace::backtrace::libunwind::trace::h89fcc71e59e3bc5b
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/libunwind.rs:88
[INFO] [stderr]    1:     0x5631a07e95ab - backtrace::backtrace::trace_unsynchronized::h0bad9be1379e729a
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/mod.rs:66
[INFO] [stderr]    2:     0x5631a07e95ab - std::sys_common::backtrace::_print::hd3382a1f33c473da
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:47
[INFO] [stderr]    3:     0x5631a07e95ab - std::sys_common::backtrace::print::h0ec6f03cfb8e76a6
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:36
[INFO] [stderr]    4:     0x5631a07e95ab - std::panicking::default_hook::{{closure}}::h96cbf7b454e3f557
[INFO] [stderr]                                at src/libstd/panicking.rs:200
[INFO] [stderr]    5:     0x5631a07e9286 - std::panicking::default_hook::h95a8f00337383d83
[INFO] [stderr]                                at src/libstd/panicking.rs:214
[INFO] [stderr]    6:     0x5631a07e9c6d - std::panicking::rust_panic_with_hook::h92f98b46e22f14ed
[INFO] [stderr]                                at src/libstd/panicking.rs:477
[INFO] [stderr]    7:     0x5631a07e97f2 - std::panicking::continue_panic_fmt::h25abfbb4e5b7043a
[INFO] [stderr]                                at src/libstd/panicking.rs:384
[INFO] [stderr]    8:     0x5631a07e96d6 - rust_begin_unwind
[INFO] [stderr]                                at src/libstd/panicking.rs:311
[INFO] [stderr]    9:     0x5631a07fe3ed - core::panicking::panic_fmt::h7e9f94035af782b3
[INFO] [stderr]                                at src/libcore/panicking.rs:85
[INFO] [stderr]   10:     0x5631a07fe4e7 - core::result::unwrap_failed::hf7591c1dd9412006
[INFO] [stderr]                                at src/libcore/result.rs:1084
[INFO] [stderr]   11:     0x5631a07af710 - core::result::Result<T,E>::unwrap::h228b4a3205550dc8
[INFO] [stderr]                                at /rustc/625451e376bb2e5283fc4741caa0a3e8a2ca4d54/src/libcore/result.rs:852
[INFO] [stderr]   12:     0x5631a07b1825 - build_script_gen_mime_types::main::haaf144cf316079aa
[INFO] [stderr]                                at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/mime_guess-1.8.3/src/gen_mime_types.rs:22
[INFO] [stderr]   13:     0x5631a079c340 - std::rt::lang_start::{{closure}}::he5b24126acc2f8f1
[INFO] [stderr]                                at /rustc/625451e376bb2e5283fc4741caa0a3e8a2ca4d54/src/libstd/rt.rs:64
[INFO] [stderr]   14:     0x5631a07e96c3 - std::rt::lang_start_internal::{{closure}}::h4e93c1949c7a1955
[INFO] [stderr]                                at src/libstd/rt.rs:49
[INFO] [stderr]   15:     0x5631a07e96c3 - std::panicking::try::do_call::h9440ccd4dc467eaa
[INFO] [stderr]                                at src/libstd/panicking.rs:296
[INFO] [stderr]   16:     0x5631a07eb62a - __rust_maybe_catch_panic
[INFO] [stderr]                                at src/libpanic_unwind/lib.rs:80
[INFO] [stderr]   17:     0x5631a07ea17d - std::panicking::try::hc046e7ee42ee744f
[INFO] [stderr]                                at src/libstd/panicking.rs:275
[INFO] [stderr]   18:     0x5631a07ea17d - std::panic::catch_unwind::h27dfc457c200aee0
[INFO] [stderr]                                at src/libstd/panic.rs:394
[INFO] [stderr]   19:     0x5631a07ea17d - std::rt::lang_start_internal::hea1b49a567afe309
[INFO] [stderr]                                at src/libstd/rt.rs:48
[INFO] [stderr]   20:     0x5631a079c319 - std::rt::lang_start::h08f0ed6306775ee0
[INFO] [stderr]                                at /rustc/625451e376bb2e5283fc4741caa0a3e8a2ca4d54/src/libstd/rt.rs:64
[INFO] [stderr]   21:     0x5631a07b2daa - main
[INFO] [stderr]   22:     0x7fe129e96b97 - __libc_start_main
[INFO] [stderr]   23:     0x5631a0787d5a - _start
[INFO] [stderr]   24:                0x0 - <unknown>
[INFO] [stderr] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "8ce07aae3c164a46e0bca7807445ca1ebc0eba77cfb395200b5246c47e498896"`
[INFO] running `"docker" "rm" "-f" "8ce07aae3c164a46e0bca7807445ca1ebc0eba77cfb395200b5246c47e498896"`
[INFO] [stdout] 8ce07aae3c164a46e0bca7807445ca1ebc0eba77cfb395200b5246c47e498896