[describe] add for actions, fix read

.github/workflows/build.yml

@@ -24,6 +24,7 @@ jobs:
       LEIN_ROOT: "true"
       BABASHKA_PLATFORM: linux # could be used in jar name
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      BABASHKA_SHA: ${{ github.sha }}
     steps:
       - name: Git checkout
         uses: actions/checkout@v2
@@ -107,6 +108,7 @@ jobs:
       BABASHKA_TEST_ENV: native
       BABASHKA_XMX: "-J-Xmx6500m"
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      BABASHKA_SHA: ${{ github.sha }}
     steps:
       - name: Git checkout
         uses: actions/checkout@v2

script/compile

@@ -107,7 +107,7 @@ then
     export BABASHKA_FEATURE_PRIORITY_MAP="${BABASHKA_FEATURE_PRIORITY_MAP:-false}"
 fi
 
-if [[ ! -f "$BABASHKA_SHA" ]]
+if [[ -z "$BABASHKA_SHA" ]]
 then
     sha=$(git rev-parse HEAD)
     if [[ $? -eq 0 ]]; then

script/compile.bat

@@ -23,7 +23,7 @@ Rem -H:EnableURLProtocols=jar,http,https is also not supported.
 
 call %GRAALVM_HOME%\bin\gu.cmd install native-image
 
-if not exist "%BABASHKA_SHA%" (
+if "%BABASHKA_SHA%"=="" (
     for /f %%i in ('git rev-parse HEAD') do set sha=%%i
     if not errorlevel 1 (
         set BABASHKA_SHA=%sha%