build: note whether binary is reproducible in each case

contrib/build-linux/README.md

@@ -1,6 +1,8 @@
 Source tarballs
 ===============
 
+✗ _This script does not produce reproducible output (yet!)._
+
 1. Build locale files
 
     ```

contrib/build-linux/appimage/README.md

@@ -1,9 +1,17 @@
 AppImage binary for Electrum
 ============================
 
+✓ _This binary should be reproducible, meaning you should be able to generate
+   binaries that match the official releases._
+
 This assumes an Ubuntu host, but it should not be too hard to adapt to another
-similar system. The docker commands should be executed in the project's root
-folder.
+similar system. The host architecture should be x86_64 (amd64).
+The docker commands should be executed in the project's root folder.
+
+We currently only build a single AppImage, for x86_64 architecture.
+Help to adapt these scripts to build for (some flavor of) ARM would be welcome,
+see [issue #5159](https://github.com/spesmilo/electrum/issues/5159).
+
 
 1. Install Docker
 

contrib/build-wine/README.md

@@ -1,10 +1,10 @@
-Deterministic Windows binaries with Docker
-==========================================
+Windows binaries
+================
 
-Produced binaries are deterministic, so you should be able to generate
-binaries that match the official releases.
+✓ _These binaries should be reproducible, meaning you should be able to generate
+   binaries that match the official releases._
 
-This assumes an Ubuntu host, but it should not be too hard to adapt to another
+This assumes an Ubuntu (x86_64) host, but it should not be too hard to adapt to another
 similar system. The docker commands should be executed in the project's root
 folder.
 
@@ -54,9 +54,6 @@ folder.
 
 
 
-Note: the `setup` binary (NSIS installer) is not deterministic yet.
-
-
 Code Signing
 ============
 

contrib/osx/README.md

@@ -1,6 +1,9 @@
 Building Mac OS binaries
 ========================
 
+✗ _This script does not produce reproducible output (yet!).
+   Please help us remedy this._
+
 This guide explains how to build Electrum binaries for macOS systems.
 
 

electrum/gui/kivy/Readme.md

@@ -5,7 +5,10 @@ To generate an APK file, follow these instructions.
 
 ## Android binary with Docker
 
-This assumes an Ubuntu host, but it should not be too hard to adapt to another
+✗ _This script does not produce reproducible output (yet!).
+   Please help us remedy this._
+
+This assumes an Ubuntu (x86_64) host, but it should not be too hard to adapt to another
 similar system. The docker commands should be executed in the project's root
 folder.