ci: Avoid pinning dependencies, use --precise

Fixes #1035

.github/workflows/cont_integration.yml

@@ -27,6 +27,9 @@ jobs:
             profile: minimal
       - name: Rust Cache
         uses: Swatinem/rust-cache@v2.2.1
+      - name: Pin dependencies for MSRV
+        if: matrix.rust.version == '1.57.0'
+        run: cargo update -p log --precise "0.4.18" && cargo update -p tempfile --precise "3.6.0"
       - name: Build
         run: cargo build ${{ matrix.features }}
       - name: Test

README.md

@@ -52,3 +52,15 @@ Fully working examples of how to use these components are in `/example-crates`
 [`rust-bitcoin`]: https://github.com/rust-bitcoin/rust-bitcoin
 [`esplora-client`]: https://docs.rs/esplora-client/0.3.0/esplora_client/
 [`electrum-client`]: https://docs.rs/electrum-client/0.13.0/electrum_client/
+
+## Minimum Supported Rust Version (MSRV)
+This library should compile with any combination of features with Rust 1.57.0.
+
+To build with the MSRV you will need to pin dependencies as follows:
+
+```
+# log 0.4.19 has MSRV 1.60.0+
+cargo update -p log --precise "0.4.18"
+# tempfile 3.7.0 has MSRV 1.63.0
+cargo update -p tempfile --precise "3.6.0"
+```

crates/bdk/Cargo.toml

@@ -13,7 +13,7 @@ edition = "2021"
 rust-version = "1.57"
 
 [dependencies]
-log = "=0.4.18"
+log = "0.4"
 rand = "^0.8"
 miniscript = { version = "9", features = ["serde"], default-features = false }
 bitcoin = { version = "0.29", features = ["serde", "base64", "rand"], default-features = false }