Merge pull request #952 from tomverbeure/compilation_instructions

Link to compilation instructions in the HTLM manual.

Author: azonenberg

README.md

@@ -10,12 +10,56 @@ Project website: [https://www.ngscopeclient.org](https://www.ngscopeclient.org)
 * [Code of Conduct](https://github.com/ngscopeclient/scopehal-apps/blob/master/CODE_OF_CONDUCT.md)
 * We are a proudly AI-free project. Only human created code is acceptable for contribution.
 
-## Installation
+## Installation 
 
 Refer to the "getting started" chapter of the User manual
 * [User manual GettingStarted (HTML)](https://www.ngscopeclient.org/manual/GettingStarted.html)
 * [User manual (PDF)](https://www.ngscopeclient.org/downloads/ngscopeclient-manual.pdf)
 
+## Compilation instructions (Linux,macOS,Windows)
+
+* [User manual Compilation (HTML)](https://www.ngscopeclient.org/manual/GettingStarted.html#compilation)
+
+## Compiling a forked repo
+
+If you want to contribute changes to scopehal-apps, you should make them in a
+forked repo so that you can create pull request with your changes.
+
+Following these steps:
+
+* Fork a bunch of GitHub repos to your own GitHub account
+
+  Right now, the build system requires that your GitHub account has cloned version of the
+  VkFFT, xptools and logtools. It's best to clone the version that under the ngscopeclient
+  account, this ensure that you're working with the same version as the core development
+  team.
+
+  * [ngscopeclient/VkFFT](https://github.com/ngscopeclient/VkFFT)
+  * [ngscopeclient/xptools](https://github.com/ngscopeclient/xptools)
+  * [ngscopeclient/logtools](https://github.com/ngscopeclient/logtools)
+
+* Fork the `scopehal-apps` repo (this one!)  to your own account
+* Clone your personal repo to your development machine
+
+  `git clone --recursive git@github.com:<your github username>/scopehal-apps.git scopehal-apps`
+
+* Follow the regular compilation instructions.
+
+  If you want to create executables with debug symbols, make sure to change option `MAKE_BUILD_TYPE`
+  from `Release` to `Debug` when running `cmake`.
+
+It is possible that `cmake` errors out with the following error message:
+
+```
+CMake Error at CMakeLists.txt:82 (message):
+  Unrecognized version tag 53152c7c / 53152c7c, can't create a VERSIONINFO
+  from it.  Must be of format v1.2, v1.2.3, v1.2-rc3, v1.2.3-rc4
+```
+
+You can fix this by creating a dummy tag in your local repo:
+
+`git tag v0.0.0`
+
 ## Special comments
 
 The following standard comments are used throughout the code to indicate things that could use attention, but are