* otherwise, unsure how to fix this; the following change
```rust
let res = unsafe { utmpxname(CString::new(f).unwrap().as_ptr()) };
```
to
```rust
let string_ptr = CString::new(f).unwrap().as_ptr();
let res = unsafe { utmpxname(string_ptr) };
```
causes three `who` tests (test_who::test_all, test_who::test_boot, and test_who::test_login)
to fail by generating no output.
- refactor internal version specifications to be ">=M.m.p" (where M.m.p is *already published*)
## [why]
Loosening internal version dependencies decreases the coupling between packages such
that packages can be published in a looser order. It allows the packages to be version
updated and published in tandem (ie, by using `cargo workspace ...`). Once published,
the internal versions can then be updated (again, to an *already published* package
version), as needed.
- more precisely describe permissable libc versions
.# [why]
- libc >= v0.2.15 is needed for utmp support.
- libc <= v0.2.66 is required to avoid build errors for MinSRV == 1.31.0.
Intermittant build failures were being caused by `cargo` using early libc versions.
- hold data-encoding to known working "<= 2.1.2"
.# [why]
data-encoding v2.2.0 causes a build error for '1.31.0-i686-pc-windows-msvc'.
```
cargo +1.31.0-i686-pc-windows-msvc build --target=i686-pc-windows-msvc --all-features
...
error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
--> C:\Users\appveyor\.cargo\registry\src\github.com-1ecc6299db9ec823\data-encoding-2.2.0\src\lib.rs:194:5
|
187 | / mod prelude {
188 | | pub use std::borrow::Cow;
189 | | }
| |_- not an extern crate passed with `--extern`
...
194 | use prelude::*;
| ^^^^^^^
|
...
```
. #[why]
Technically, by semver rules, projects with versions < v1.0.0 may make breaking
changes with *any* version change. So, for some protection, pin all crates with
version < v1.0.0 to a specific version.
* ref: <https://semver.org> @@ <https://archive.is/LTGHB>
