Revert var.sh and change fetch-depth to 0 in workflow

.github/workflows/main.yml

@@ -17,6 +17,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
+          fetch-depth: 0
           submodules: recursive
       - name: Build FFMpeg
         shell: bash
@@ -31,6 +32,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
+          fetch-depth: 0
           submodules: recursive
       - name: Setup cache
         id: cache-system-libraries

wasm/build-scripts/var.sh

@@ -7,8 +7,6 @@ set -euo pipefail
 # Include llvm binaries
 export PATH=$PATH:$EMSDK/upstream/bin
 
-export PKG_CONFIG_PATH=$PWD/build/lib/pkgconfig
-
 # Flags for code optimization, focus on speed instead
 # of size
 OPTIM_FLAGS=(