Merge BlockstreamResearch#261: Switch to cargo-fuzz

ae12708 chore: Delete fuzz nix shells (Christian Lewe)
98430c2 chore: Add cargo-fuzz files to .gitignore (Christian Lewe)
6362db7 refactor: Update fuzz scripts (Christian Lewe)
9d05999 refactor: Port fuzz crate to cargo-fuzz (Christian Lewe)
2aa015f chore: Bump MSRV 1.63.0 -> 1.78.0 (Christian Lewe)

Pull request description:

  Adapt the fuzzing infrastructure to use cargo-fuzz. I keep the existing shell scripts because they turned out to be useful.

  Everything should work as before, except that the `fuzzing` flag is producing warnings when the tests are run. Let's discuss solutions here.

ACKs for top commit:
  apoelstra:
    ACK ae12708

Tree-SHA512: 0a85e42ff7c08f682e7d4697bb2183a24915d9baa2486d5a7f7bc00d5ab5d20a634fda452efc5209466626c22a3ceff9de2deef736d879e183fb8929c1923917

Author: apoelstra

.github/workflows/fuzz.yml

@@ -23,9 +23,6 @@ decode_program,
 parse_human,
         ]
     steps:
-      - name: Install test dependencies
-        run: sudo apt-get update -y && sudo apt-get install -y binutils-dev libunwind8-dev libcurl4-openssl-dev libelf-dev libdw-dev cmake gcc libiberty-dev
-
       - name: Checkout Crate
         uses: actions/checkout@v4
 
@@ -38,15 +35,18 @@ parse_human,
             fuzz/target
             target
           key: cache-${{ matrix.target }}-${{ hashFiles('**/Cargo.toml','**/Cargo.lock') }}
+
       - name: Install Toolchain
-        uses: dtolnay/rust-toolchain@stable
+        uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: '1.65.0'
+          toolchain: nightly-2024-07-01
+          components: "llvm-tools-preview"
+
+      - name: Install Dependencies
+        run: cargo update && cargo update -p cc --precise 1.0.83 && cargo install cargo-fuzz
 
       - name: Run Fuzz Target
-        run: |
-          echo "Using RUSTFLAGS $RUSTFLAGS"
-          cd fuzz && cargo update && cargo update -p cc --precise 1.0.83 && ./fuzz.sh "${{ matrix.fuzz_target }}"
+        run: ./fuzz/fuzz.sh "${{ matrix.fuzz_target }}"
 
       - name: Prepare Artifact
         run: echo "${{ matrix.fuzz_target }}" >executed_${{ matrix.fuzz_target }}

.github/workflows/main.yml

@@ -54,7 +54,7 @@ jobs:
           - stable
           - beta
           - nightly
-          - 1.63.0
+          - 1.78.0
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4

.gitignore

@@ -10,6 +10,8 @@ Cargo.lock
 #fuzz
 fuzz/hfuzz_target
 fuzz/hfuzz_workspace
+fuzz/artifacts
+fuzz/corpus
 
 #IntelliJ project files
 .idea