elias@eliasgentoo ~/Downloads/RustBug $ sudo emerge -pqv '=dev-lang/rust-1.32.0::gentoo'
[ebuild     U ] dev-lang/rust-1.32.0 [1.29.1-r1] USE="-clippy -debug -doc -libressl -rls -rustfmt -system-llvm% -wasm (-cargo%) (-jemalloc%*)" ABI_X86="(64) -32 (-x32)" CPU_FLAGS_X86="sse2" LLVM_TARGETS="(X86) -AArch64 -AMDGPU -ARM -BPF -Hexagon -Lanai -MSP430 -Mips -NVPTX -PowerPC -Sparc -SystemZ -XCore" 
[blocks B     ] dev-util/cargo ("dev-util/cargo" is blocking dev-lang/rust-1.32.0)

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

dev-lang/rust:stable

  (dev-lang/rust-1.32.0:stable/1.32::gentoo, ebuild scheduled for merge) pulled in by
    =dev-lang/rust-1.32.0::gentoo (Argument)

  (dev-lang/rust-1.29.1-r1:stable/1.29::gentoo, installed) pulled in by
    =dev-lang/rust-1.29.1* required by (virtual/rust-1.29.1:0/0::gentoo, installed)
    ^              ^^^^^^^                                                                                                                



 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (dev-util/cargo-0.30.0:0/0::gentoo, installed) pulled in by
    >=dev-util/cargo-0.30.0 required by (dev-lang/rust-1.29.1-r1:stable/1.29::gentoo, installed)
    =dev-util/cargo-0.30.0* required by (virtual/cargo-1.29.1:0/0::gentoo, installed)