[INFO] updating cached repository Bert-Proesmans/syn-issue
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Bert-Proesmans/syn-issue
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Bert-Proesmans/syn-issue" "work/ex/beta-1.38-1/sources/1.37.0/gh/Bert-Proesmans/syn-issue"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Bert-Proesmans/syn-issue'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Bert-Proesmans/syn-issue" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Bert-Proesmans/syn-issue"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Bert-Proesmans/syn-issue'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e72b592c0128d8be110cafafa2aee637c056fea2
[INFO] sha for GitHub repo Bert-Proesmans/syn-issue: e72b592c0128d8be110cafafa2aee637c056fea2
[INFO] validating manifest of Bert-Proesmans/syn-issue on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Bert-Proesmans/syn-issue on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing Bert-Proesmans/syn-issue
[INFO] removed path dependency proc_macro from Bert-Proesmans/syn-issue
[INFO] finished frobbing Bert-Proesmans/syn-issue
[INFO] frobbed toml for Bert-Proesmans/syn-issue written to work/ex/beta-1.38-1/sources/1.37.0/gh/Bert-Proesmans/syn-issue/Cargo.toml
[INFO] started frobbing Bert-Proesmans/syn-issue
[INFO] removed path dependency proc_macro from Bert-Proesmans/syn-issue
[INFO] finished frobbing Bert-Proesmans/syn-issue
[INFO] frobbed toml for Bert-Proesmans/syn-issue written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Bert-Proesmans/syn-issue/Cargo.toml
[INFO] crate Bert-Proesmans/syn-issue already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr] error: no matching package named `proc_macro` found
[INFO] [stderr] location searched: registry `https://github.com/rust-lang/crates.io-index`
[INFO] [stderr] required by package `syn_issue v0.1.0 (/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Bert-Proesmans/syn-issue)`
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed