further ARM64 updates

Author: csoeller

Installing-PYME-with-py3-macos-ARM64.md

@@ -1,5 +1,7 @@
 ## Instructions to install PYME natively on macos ARM64 (M1, M2 etc)
 
+### Installing miniconda and xcode command line tools
+
 Everything is generally done in a terminal window that runs natively.
 
 We start with a native miniconda install:
@@ -13,6 +15,8 @@ That installed a small base install with Python 3.9.
 
 Then I picked up the `xcode` command-line tools which is quite easy. There are a number of ways, a very easy one is just to type a command like `clang` at the terminal prompt and then you are immediately prompted/asked if you would like to install the xcode command line tools. See also https://www.freecodecamp.org/news/install-xcode-command-line-tools/. 
 
+### Installing PYME proper
+
 I made an environment to build PYME in and based that on Python 3.8 as a well tested version according to David Baddeley:
 
 ```shell
@@ -50,3 +54,31 @@ dh5view -t
 ```
 
 This seems to give a working install, still testing but most things with `dh5view` and `PYMEVis` seem fine.
+
+### Getting jupyter notebook support going
+
+This needed another quick conda install:
+
+```shell
+conda install -c conda-forge notebook
+```
+
+I then tried opening a new python3 notebook and got an error:
+
+```
+500 : Internal Server Error
+```
+
+A quick google led me to this [stackoverflow discussion](https://stackoverflow.com/questions/36851746/jupyter-notebook-500-internal-server-error) which suggested to run
+
+```
+conda install nbconvert==5.4.1
+```
+
+Now, I am not sure that the pinned version is still the best option (the previous conda command had installed version `nbconvert-5.6.1`), but I gave it a go anyway (leaving the option to tweak to a later version once it is clear in which version the issue occurs) and did
+
+```shell
+conda install -c conda-forge nbconvert==5.4.1
+```
+
+which indeed fixed the issue and now I can open notebooks just fine.