acme-client depends on an old version of reqwest which in turn depends on an old version of the openssl crate. The old openssl crate is not able to use at least openssl 1.1.1 (I don't know the exact version where it stops working)
thread 'main' panicked at 'Unable to detect OpenSSL version', /.../registry/src/github.com-1ecc6299db9ec823/openssl-0.9.24/build.rs:16:14
stack backtrace:
0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: std::sys_common::backtrace::print
at libstd/sys_common/backtrace.rs:71
at libstd/sys_common/backtrace.rs:59
2: std::panicking::default_hook::{{closure}}
at libstd/panicking.rs:211
3: std::panicking::default_hook
at libstd/panicking.rs:227
4: std::panicking::rust_panic_with_hook
at libstd/panicking.rs:476
5: std::panicking::begin_panic
6: build_script_build::main
7: std::rt::lang_start::{{closure}}
8: std::panicking::try::do_call
at libstd/rt.rs:59
at libstd/panicking.rs:310
9: __rust_maybe_catch_panic
at libpanic_unwind/lib.rs:102
10: std::rt::lang_start_internal
at libstd/panicking.rs:289
at libstd/panic.rs:392
at libstd/rt.rs:58
11: main
12: __libc_start_main
13: _start
acme-client depends on an old version of reqwest which in turn depends on an old version of the openssl crate. The old openssl crate is not able to use at least openssl 1.1.1 (I don't know the exact version where it stops working)