Linking error on Windows 11 using Intel MKL as static library

Start with the example crate's Cargo.toml crate-type combinations and src/lib.rs, then run cargo build on the stated Windows MSVC environment with intel-mkl-static enabled. Compare the failing and working configurations and inspect the linker output. Done means the reported crate-type combinations link consistently without unresolved cblas symbols.

When compiling a small crate against ndarray-linalg using the intel-mkl-static feature, linking errors result depending on the value of lib.crate-type in Cargo.toml.

Example crate

// src/lib.rs
use num_complex::Complex64 as c64;
use ndarray::{Array2, ArrayView2};

pub trait HasDagger {
    type Output;

    fn dag(&self) -> Self::Output;
}

impl HasDagger for Array2<c64> {
    type Output = Self;

    fn dag(&self) -> Self {
        self.t().map(|element| element.conj())
    }
}

impl HasDagger for ArrayView2<'_, c64> {
    type Output = Array2<c64>;

    fn dag(&self) -> Self::Output {
        self.t().map(|element| element.conj())
    }
}

pub trait ConjBy {
    fn conjugate_by(&self, op: &ArrayView2<c64>) -> Self;
}

impl ConjBy for Array2<c64> {
    fn conjugate_by(&self, op: &ArrayView2<c64>) -> Self {
        op.dot(self).dot(&op.dag())
    }
}

[package]
name = "blas-rs"
version = "0.0.1"
edition = '2018'

[lib]
crate-type = [
    'rlib',
    'staticlib',
    'cdylib',
]

[dependencies]
anyhow = '<1.0.49'

[dependencies.ndarray]
version = '0.15.4'
features = ['serde']

[dependencies.num-complex]
version = '0.4'
features = ['serde']

[dependencies.serde]
version = '1.0'
features = ['derive']

[dependencies.ndarray-linalg]
version = '0.14.1'
features = ['intel-mkl-static']

Example error:

$ cargo build
➜  cargo build
   Compiling blas-rs v0.0.1 (C:\Users\cgran\source\scratch\blas-rs)
warning: Error finalizing incremental compilation session directory `\\?\C:\Users\cgran\source\scratch\blas-rs\target\debug\incremental\blas_rs-204zbe9n3gp6o\s-g6at8u30m7-1gpl7ds-working`: Access is denied. (os error 5)

error: linking with `link.exe` failed: exit code: 1120
  |
  = note: "C:\\Program Files (x86)\\Microsoft Visual Studio\\2019\\Enterprise\\VC\\Tools\\MSVC\\14.29.30133\\bin\\HostX64\\x64\\link.exe"
  = note:    Creating library C:\...\target\debug\deps\blas_rs.dll.lib and object C:\...\target\debug\deps\blas_rs.dll.exp
          blas_rs.pi0kkv54xyu470e.rcgu.o : error LNK2019: unresolved external symbol cblas_sgemm referenced in function _ZN7ndarray6linalg11impl_linalg12mat_mul_impl17h80b4dcd4e156b29cE
          blas_rs.pi0kkv54xyu470e.rcgu.o : error LNK2019: unresolved external symbol cblas_dgemm referenced in function _ZN7ndarray6linalg11impl_linalg12mat_mul_impl17h80b4dcd4e156b29cE
          blas_rs.pi0kkv54xyu470e.rcgu.o : error LNK2019: unresolved external symbol cblas_cgemm referenced in function _ZN7ndarray6linalg11impl_linalg12mat_mul_impl17h80b4dcd4e156b29cE
          blas_rs.pi0kkv54xyu470e.rcgu.o : error LNK2019: unresolved external symbol cblas_zgemm referenced in function _ZN7ndarray6linalg11impl_linalg12mat_mul_impl17h80b4dcd4e156b29cE
          C:\Users\cgran\source\scratch\blas-rs\target\debug\deps\blas_rs.dll : fatal error LNK1120: 4 unresolved externals


warning: `blas-rs` (lib) generated 1 warning
error: could not compile `blas-rs` due to previous error; 1 warning emitted

Running cargo build works for some settings of lib.crate-type, however:

• ["rlib", "staticlib", "cdylib"]: fails
• ["staticlib", "cdylib"]: works
• ["rlib", "staticlib"]: works
• ["rlib"]: works
• ["staticlib"]: works
• ["rlib", "cdylib"]: fails
• ["cdylib"]: works

Version info

➜ cargo --version
cargo 1.57.0 (b2e52d7ca 2021-10-21)

➜ rustup show
Default host: x86_64-pc-windows-msvc
rustup home:  C:\...\.rustup

installed toolchains
--------------------

stable-x86_64-pc-windows-msvc
nightly-x86_64-pc-windows-msvc

installed targets for active toolchain
--------------------------------------

x86_64-apple-darwin
x86_64-pc-windows-gnu
x86_64-pc-windows-msvc
x86_64-unknown-linux-gnu

active toolchain
----------------

stable-x86_64-pc-windows-msvc (default)
rustc 1.57.0 (f1edd0429 2021-11-29)