chore: Attempt to make reproducible builds

Rustc still does not have complete support for fully reproducible builds
(rust-lang/rust#75362). Attempt to narrow the
gap by following the advice from
(rust-lang/rust#102299) and overwrite all
panic paths with a different, consistent value.

you-have-mail-android/app/build.gradle

@@ -13,8 +13,8 @@ android {
         applicationId "dev.lbeernaert.youhavemail"
         minSdk 29
         targetSdk 33
-        versionCode 19
-        versionName "0.7.1"
+        versionCode 20
+        versionName "0.7.2"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables {
@@ -89,6 +89,13 @@ cargo {
     /*features {
         defaultAnd("null_backend")
     }*/
+
+    // Ensure paths are consistent for reproducible builds.
+    exec { spec, _ ->
+        var home = "$System.env.HOME"
+        var pwd = "$System.env.PWD"
+        spec.environment("RUSTFLAGS", "--remap-path-prefix=${home}=/remap-home --remap-path-prefix=${pwd}=/remap-pwd")
+    }
 }
 
 tasks.whenTaskAdded { task ->

you-have-mail-common/Cargo.toml

@@ -22,7 +22,7 @@ secrecy = "0.8"
 crossbeam-channel = "0.5"
 
 [dependencies.proton-api-rs]
-version = "0.8.0"
+version = "0.8.1"
 optional = true
 features = ["http-ureq"]