Currently we are unable to build with all features enabled with a
non-nightly toolchain, this is because of the use of
`#![cfg_attr(all(test, feature = "unstable"), feature(test))]`
which causes the following error when building:
error[E0554]: `#![feature]` may not be used on the stable release
channel
The "unstable" feature is used to guard bench mark modules, this is
widely suggested online but there is a better way.
When running the bench marks use the following incantation:
`RUSTFLAGS='--cfg=bench' cargo bench`
This creates a configuration conditional "bench" that can be used to
guard the bench mark modules.
#[cfg(bench)]
mod benches {
...
}
If CI script is run with `DO_BENCH=true` and `TOOLCHAIN` set to a
non-nightly toolchain the build will fail with a less than meaningful
error. To assist runners of the script output an informative error
message if an attempt is made at using the wrong toolchain.
The docs lint `broken-intra-doc-links` has been changed but the new name
is not available in our MSRV, this means we get a build warning. We only
build docs with the nightly toolchain so we can move this lint control
to the docs build command in `test.sh` instead of doing it crate wide.
With this patch applied devs risk not noticing docs link issues until
they hit them on CI _if_ they do not build with the test script or
explicitly pass in `-- -D rustdoc::broken-intra-doc-links`, which no one
is going to do. Hence we add a line to the readme with a shell alias
that can be used to check docs, taken directly from `test.sh`.
Features activating external crates are supposed to have same name as
those crates. However we depend on same feature in other crates so we
need a separate feature. After MSRV bump it is possible to rename the
crates and features so we can now fix this inconsistency.
Sadly, derive can't see that the crate was renamed so all derives must
be told to use the other one.
We currently build the docs as a separate CI job, we can however just do
it as part of the `Tests` job using the nightly toolchain.
Conditionally build the docs based on a `DO_DOCS` env var.
Note, uses `--cfg docsrs` so can only be built run with nightly toolchain.
Based on the original work by Justin Moon.
*MSRV unchanged from 1.29.0.*
When `std` is off, `no-std` must be on, and we use the [`alloc`](https://doc.rust-lang.org/alloc/) and core2 crates. The `alloc` crate requires the user define a global allocator.
* Import from `core` and `alloc` instead of `std`
* `alloc` only used if `no-std` is on
* Create `std` feature
* Create `no-std` feature which adds a core2 dependency to polyfill `std::io` features. This is an experimental feature and should be
used with caution.
* CI runs tests `no-std`
* MSRV for `no-std` is 1.51 or so
By exposing this, we can use the 'rand' dependency of secp256k1
in a project that only depends on rust-bitcoin without having to
add a separate dependency in order to activate the feature flag.