Fails to build with the new allocator system

[zkbpkp]

xargo build throws an error while compiling ralloc dependency:

   Compiling ralloc v1.0.0 (https://github.com/redox-os/ralloc#a93871cd)
error[E0557]: feature has been removed
  --> /home/boss/.cargo/git/checkouts/ralloc-797ee1a3f928155b/a93871c/src/lib.rs:18:12
   |
18 | #![feature(allocator, const_fn, core_intrinsics, stmt_expr_attributes, drop_types_in_const,
   |            ^^^^^^^^^

error: The attribute `allocator` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
  --> /home/boss/.cargo/git/checkouts/ralloc-797ee1a3f928155b/a93871c/src/lib.rs:12:36
   |
12 | #![cfg_attr(feature = "allocator", allocator)]
   |                                    ^^^^^^^^^^
   |
   = help: add #![feature(custom_attribute)] to the crate attributes to enable

error: aborting due to 2 previous errors

error: Could not compile `ralloc`.

Related issue: https://github.com/redox-os/ralloc/issues/56

[japaric]

naive_ralloc, our in-tree dumb allocator, has been updated to work with the new allocator system so you can use that until ralloc is updated. To do that compile steed with default-features = false and features = ["naive_ralloc"].

[japaric]

compile steed with default-features = false and features = ["naive_ralloc"].

Add those two lines to the Xargo.toml you are using, under the [dependencies.std] header

[radix]

It seems that the dependency on ralloc is not pinned to a specific revision. Shouldn't it be?