Reproducible Builds

[IzzySoft]

At IzzyOnDroid we support Reproducible Builds (see: Reproducible Builds, special client support and more at IzzyOnDroid). Trying for yours, I was able to successfully generate the APK using ./gradlew assembleRelease, but the resulting APKs were not identical. Today, I found the culprit:

gn_mobile_occtax/occtax/build.gradle

Line 36 in ef398ac

buildConfigField "String", "BUILD_DATE", "\"" + new Date().getTime() + "\""

       name          : 'BUILD_DATE'
       type          : 'Ljava/lang/String;'
       access        : 0x0019 (PUBLIC STATIC FINAL)
-      value         : "1720875836589"
+      value         : "1720955749028"
     #2              : (in Lfr/geonature/occtax/BuildConfig;)
       name          : 'BUILD_TYPE'
       type          : 'Ljava/lang/String;'

As that's calculated at build time, it prevents the app from being reproducible. With the current v2.7.1 there was an added minor culprit (the APK was built before the last changes have been committed) – but the following recipe lead to a successful RB:

- git reset --soft a2df18b643390014b0427bdbccfe35e101168516
- sed -r '/signingConfigs.release/d' -i occtax/build.gradle
- sed -r 's/new Date\(\)\.getTime\(\)/1731849775420/' -i occtax/build.gradle
- chmod +x gradlew
- ./gradlew assembleRelease
- mv occtax/build/outputs/apk/release/occtax-*-release-unsigned.apk /outputs/unsigned.apk

results in

BUILD SUCCESSFUL in 4m
300 actionable tasks: 300 executed
+ mv occtax/build/outputs/apk/release/occtax-2.7.1-release-unsigned.apk /outputs/unsigned.apk

--- END BUILD LOG ---
Keeping 'd49d7c555be718501b3d359a4e205478a20ee7f5a6ffdfa8bf922e6e62ebd20b-fr.geonature.occtax2-2.7.1-upstream.apk'...
Keeping '9511ec987b6c8fe25b0e6fd85cb6cf28ceb608f0762b3c89edaaebba4cdfdb49-fr.geonature.occtax2-2.7.1-unsigned.apk'...
Reproducible: True
Tags built: 1.

May I kindly ask you to remove that BUILD_DATE field, to allow newer releases to be automatically verified for RB (eh, and also to build from a clean tree after having the latest changes committed)? Thanks in advance!