Where does cargo put shared libraries? #3660
Description
So we had kind of a situation over at imag.
What happened
We had this PR https://github.com/matthiasbeyer/imag/pull/871 for introducing Ruby bindings for imag (using the awesome ruru crate), which are build with the thermite Ruby gem helper, which packs .sos into a gem. As you can see, the PR 871 succeeded on travis, so I merged it.
Master was broken instantly, because thermite couldn't find the liblibimagruby.so anymore (which it could find on PR 871).
So I opened https://github.com/matthiasbeyer/imag/pull/894 to revert the whole thing and merged it as soon as travis succeeded.
Then I opened https://github.com/matthiasbeyer/imag/pull/895, cherry-picked each commit from the initial https://github.com/matthiasbeyer/imag/pull/871 and pushed it. Travis failed again.
What I can see
We build against Rust 1.13, Beta and Stable. All have to succeed to get a CI-OK.
The table below shows the rustc/cargo versions for the specific builds. The failing builds (stable) use the same cargo and rustc as the succeeding build from the PR 871.
| PR | travsi-jobset | build | rustc | cargo | status |
|---|---|---|---|---|---|
| 871 | 198740111 | 1.13 | rustc 1.13.0 (2c6933acc 2016-11-07) | cargo 0.13.0-nightly (eca9e15 2016-11-01) | succeeded |
| 871 | 198740111 | Beta | rustc 1.16.0-beta.1 (5276ba72e 2017-01-31) | cargo-0.17.0-nightly (dfc0f95 2017-02-01) | succeeded |
| 871 | 198740111 | Stable | rustc 1.15.0 (10893a9a3 2017-01-19) | cargo 0.16.0-nightly (6e0c18c 2017-01-27) | succeeded |
| master | 198837920 | 1.13 | rustc 1.13.0 (2c6933acc 2016-11-07) | cargo 0.13.0-nightly (eca9e15 2016-11-01) | succeeded |
| master | 198837920 | Beta | rustc 1.16.0-beta.1 (5276ba72e 2017-01-31) | cargo-0.17.0-nightly (dfc0f95 2017-02-01) | succeeded |
| master | 198837920 | Stable | rustc 1.15.0 (10893a9a3 2017-01-19) | cargo 0.16.0-nightly (6e0c18c 2017-01-27) | failed |
| 895 | 198869296 | 1.13 | rustc 1.13.0 (2c6933acc 2016-11-07) | cargo 0.13.0-nightly (eca9e15 2016-11-01) | succeeded |
| 895 | 198869296 | Beta | rustc 1.16.0-beta.1 (5276ba72e 2017-01-31) | cargo-0.17.0-nightly (dfc0f95 2017-02-01) | succeeded |
| 895 | 198869296 | Stable | rustc 1.15.0 (10893a9a3 2017-01-19) | cargo 0.16.0-nightly (6e0c18c 2017-01-27) | failed |
The failed PRs fail because thermite cannot find the liblibimagruby.so.
As you can see, it seems to have failed out of nowhere. There were no other PRs merged during these merges.
I reproduced the error on a VM using
cargo 0.17.0
rustc 1.16.0-nightly
The liblibimagruby.so lives in /target/debug/deps/liblibimagruby.so, but is expected to be in /target/debug/liblibimagruby.so.
Can someone help me investigate?
(Notice: Workspaces involved!)
How to reproduce
I'm not sure. I guess it would be enough to call bundle install --path vendor/bundle in /libimagruby and then make lib-imag-ruby-test in the root directory of the project. (We use make to automate cargo calls and also because we have to call bundle exec rake thermite:tarball in between).
(I do not test this on my local machine because I use distro-package rustc/cargo and I'm still on 1.14, where everything works fine as far as I can see)