Try CI in a Docker container tonsky/firacode:latest

.github/workflows/build.yml

@@ -1,17 +1,14 @@
-name: Build Fira Code
-
 on: [push]
-
 jobs:
   build:
     runs-on: ubuntu-latest
-    name: Build
+    container: tonsky/firacode:latest
     steps:
     - uses: actions/checkout@v2
-    - run: echo "FIRA_CODE_VERSION=$(python3 ./script/version.py)" >> $GITHUB_ENV
-    - run: ./script/bootstrap_linux.sh
+    - run: echo ${GITHUB_REF#refs/heads/}
+    - run: echo "version=$(git rev-parse --short $GITHUB_SHA)" >> $GITHUB_ENV
     - run: ./script/build.sh
     - uses: actions/upload-artifact@v2
       with:
-        name: Fira_Code_v${{ env.FIRA_CODE_VERSION }}
+        name: Fira_Code_${{ env.version }}
         path: distr

Dockerfile

@@ -2,12 +2,8 @@ FROM python:3
 
 WORKDIR /opt
 
-RUN pip install -U Pillow==5.4.1 idna==2.8 requests==2.21.0 urllib3==1.24.1
-RUN pip install pycairo
-RUN pip install git+https://github.com/googlefonts/gftools
-RUN pip install fontmake
+RUN pip install --upgrade Pillow==5.4.1 idna==2.8 requests==2.21.0 urllib3==1.24.1 pycairo==1.20.1 gftools==0.7.4 fontmake==2.4.0 fontbakery==0.8.0
 RUN apt-get update && \
     apt-get install -y ttfautohint && \
     apt-get install -y woff2 && \
-    apt-get install -y sfnt2woff-zopfli
-RUN pip install fontbakery
+    apt-get install -y sfnt2woff-zopfli

FiraCode.glyphs

@@ -131396,7 +131396,6 @@ instanceInterpolations = {
 name = Regular;
 },
 {
-exports = 0;
 customParameters = (
 {
 name = weightClass;