Compilation Errors - error: variable does not need to be mutable

[Thireus]

Compilation failed on armv7l host with master head at 4bbaa8d.

   Compiling grin_core v0.2.0 (file:///home/thireus/grin/core)
warning: use of deprecated item: underlying aggsig api still subject to review and change
   --> core/src/core/transaction.rs:194:12
    |
194 |    valid = secp::aggsig::verify_single(&secp, &sig, &msg, None, &pubkeys[i], false);
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: #[warn(deprecated)] on by default

warning: use of deprecated item: Experimental - underlying code unreviewed and subject to change
   --> core/src/core/transaction.rs:952:14
    |
952 |   match secp.verify_bullet_proof(self.commit, self.proof, None) {
    |              ^^^^^^^^^^^^^^^^^^^

error: variable does not need to be mutable
   --> core/src/core/transaction.rs:528:7
    |
528 |   let mut keys = kernel_offsets
    |       ---^^^^^
    |       |
    |       help: remove this `mut`
    |
note: lint level defined here
   --> core/src/lib.rs:21:9
    |
21  | #![deny(unused_mut)]
    |         ^^^^^^^^^^

error: variable does not need to be mutable
   --> core/src/core/transaction.rs:602:7
    |
602 |   let mut keys = kernel_offsets
    |       ---^^^^^
    |       |
    |       help: remove this `mut`

error: variable does not need to be mutable
   --> core/src/core/transaction.rs:662:7
    |
662 |   let mut positive_key = vec![mk_tx.offset]
    |       ---^^^^^^^^^^^^^
    |       |
    |       help: remove this `mut`

error: variable does not need to be mutable
   --> core/src/core/transaction.rs:668:7
    |
668 |   let mut negative_keys = kernel_offsets
    |       ---^^^^^^^^^^^^^^
    |       |
    |       help: remove this `mut`

error: aborting due to 4 previous errors

error: Could not compile `grin_core`.
warning: build failed, waiting for other jobs to finish...
error: build failed

[ignopeverell]

What does rustc --version give you? You should have at least 1.24.

[Thireus]

Well spotted, thank you Ignotus!

I was on rustc 1.22.1. I did a rustup default 1.25.0 to upgrade (rustup update on 1.26.0 didn't work for ARM --> rust-lang/rustup#1410).