force GSL 2.7.1 version

.github/workflows/docker-compile-ubuntu.yml

@@ -33,7 +33,16 @@ jobs:
       - name: Check output
         run: echo branch ${{ steps.vars.outputs.short_ref }}
 
-      - name: GSL
+      - name: Install GSL 2.7.1
+        run: |
+          wget https://ftp.gnu.org/gnu/gsl/gsl-2.7.1.tar.gz
+          tar -xf gsl-2.7.1.tar.gz
+          cd gsl-2.7.1/
+          ./configure
+          make
+          make install
+
+      - name: Show GSL version
         run: |
           gsl-config --libs
           gsl-config --version

.github/workflows/ubuntu-18.04-compile.yml

@@ -18,6 +18,20 @@ jobs:
         sudo apt update
         sudo apt install -y build-essential git make cmake clang libgflags-dev zlib1g-dev libssl-dev libreadline-dev libmicrohttpd-dev pkg-config libgsl-dev python3 python3-dev ninja-build
 
+    - name: Install GSL 2.7.1
+      run: |
+        wget https://ftp.gnu.org/gnu/gsl/gsl-2.7.1.tar.gz
+        tar -xf gsl-2.7.1.tar.gz
+        cd gsl-2.7.1/
+        ./configure
+        make
+        make install
+
+    - name: Show GSL version
+      run: |
+        gsl-config --libs
+        gsl-config --version
+
     - name: Configure & Build
       run: |
         export CC=$(which clang)

.github/workflows/ubuntu-compile.yml

@@ -20,6 +20,21 @@ jobs:
       run: |
         sudo apt update
         sudo apt install -y build-essential git make cmake clang libgflags-dev zlib1g-dev libssl-dev libreadline-dev libmicrohttpd-dev pkg-config libgsl-dev python3 python3-dev ninja-build
+
+    - name: Install GSL 2.7.1
+      run: |
+        wget https://ftp.gnu.org/gnu/gsl/gsl-2.7.1.tar.gz
+        tar -xf gsl-2.7.1.tar.gz
+        cd gsl-2.7.1/
+        ./configure
+        make
+        make install
+
+    - name: Show GSL version
+      run: |
+        gsl-config --libs
+        gsl-config --version
+
     - name: Configure & Build
       run: |
         export CC=$(which clang)