[CI] Compile bitcoin from source (slow\!)

tests/conftest.py

@@ -103,7 +103,7 @@ def run_bitcoind():
     # Run bitcoind in a separate folder
     os.makedirs(BITCOIN_DIRNAME, exist_ok=True)
 
-    bitcoind = os.getenv("BITCOIND", "/bitcoin/bin/bitcoind")
+    bitcoind = os.getenv("BITCOIND", "bitcoind")
 
     shutil.copy(os.path.join(os.path.dirname(__file__),
                 "bitcoin.conf"), BITCOIN_DIRNAME)

tests/setup_script.sh

@@ -1,9 +1,13 @@
 #!/bin/bash
 
 sudo apt update -y && sudo apt install -y curl
-curl -o /tmp/bitcoin.tar.gz https://bitcoincore.org/bin/bitcoin-core-26.0/bitcoin-26.0-x86_64-linux-gnu.tar.gz && \
-    sudo tar -xf /tmp/bitcoin.tar.gz -C / && \
-    sudo mv /bitcoin-26.0 /bitcoin
 
-# Add bitcoin binaries to path
-export PATH=/bitcoin/bin:$PATH
+cd /tmp
+git clone --depth=1 https://github.com/achow101/bitcoin.git -b musig2
+cd bitcoin
+sudo apt-get install build-essential cmake pkg-config python3
+sudo apt-get install libevent-dev libboost-dev
+sudo apt install libsqlite3-dev
+cmake -B build
+cmake --build build
+cmake --install build