change startup.jl

docs/src/startup.md

@@ -1,18 +1,21 @@
 # REPL tips at startup.jl
 
-This is my current (as of September 2023) `.julia/config/startup.jl` file:
+This is my current (as of November 2023) `.julia/config/startup.jl` file:
 
 ```julia
-using Revise, BenchmarkTools
+using Revise
+using BenchmarkTools
 import OhMyREPL
+OhMyREPL.colorscheme!("TomorrowNightBright")
 import Pkg
 Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
-insert!(LOAD_PATH, 2, mktempdir())
-OhMyREPL.colorscheme!("TomorrowNightBright")
+if occursin(splitpath(Base.active_project())[end-1],"v"*string(VERSION))
+    Pkg.activate(temp=true)
+end
 ```
 
 - `Revise` and `BenchmarkTools` are important development tools.
-- `OhMyREPL` is responsible for syntax highlighting in the REPL. 
+- `OhMyREPL` is responsible for syntax highlighting in the REPL, and that is my preferred color scheme.
 
 Install first these packages with:
 
@@ -25,15 +28,32 @@ the latest version of every package all the time when installing a package in
 a new environment. This is nice to avoid many unnecessary downloading and 
 recompilation runs. 
 
-With `insert!(LOAD_PATH, 2, mktempdir())`, a temporary environment is added 
+The code
+```julia
+if occursin(splitpath(Base.active_project())[end-1],"v"*string(VERSION))
+    Pkg.activate(temp=true)
+end
+```
+will check if the active environment is the main one ("v1.10", or similar) and,
+in this case, activate a temporary environment instead. 
+With that adding new packages does not bloat the Main environment. 
+This is very convenient for testing new
+packages. Now (as of Julia 1.9) that precompiled cache files are saved, installing
+packages that are already locally available is quick, and thus having a default
+temporary environment is quite convenient. 
+
+A few time ago I used, instead of `Pkg.activate(temp=true)`, 
+```
+insert!(LOAD_PATH, 2, mktempdir())
+```
+with which a temporary environment is added 
 to the list of default environments. This is useful because, when installing
 a package automatically after a `using Package` command, one is prompted (by chossing the `o`)
 in which environment the package is to be installed. Choosing the tempororary 
 one (which will be selected by default) will avoid clutering the global environment.
 In combination with the above update-registry option, this avoids may recompilation
-runs.
+runs. But currently I prefer just always starting in a temporary environment.
 
-The last line is my preferred color scheme.