What causes a breakpoint to fail to bind? - f#

Question

What causes a breakpoint to fail to bind?
I receive an error when attempting to execute the following expression:
let grid_1 = { grid with Four= grid |> update };; // Updated here
The error I receive is as follows:
Code:
type State = Alive | Dead
type Response = | Survives
| Dies
| Resurected
type Grid = { Zero:State
One:State
Two:State
Three:State
Four:State // Central
Five:State
Six:State
Seven:State
Eight:State }
let isUnderPopulated (grid:Grid) =
let zero = if grid.Zero = Alive then 1 else 0
let one = if grid.One = Alive then 1 else 0
let two = if grid.Two = Alive then 1 else 0
let three = if grid.Three = Alive then 1 else 0
let four = if grid.Four = Alive then 1 else 0
let five = if grid.Five = Alive then 1 else 0
let six = if grid.Six = Alive then 1 else 0
let seven = if grid.Seven = Alive then 1 else 0
let eight = if grid.Eight = Alive then 1 else 0
let livingCount = zero + one + two + three + four + five + six + seven + eight
livingCount < 2
let grid = { Zero = Dead
One = Dead
Two = Dead
Three = Dead
Four = Dead
Five = Dead
Six = Dead
Seven = Dead
Eight = Dead }
let update (grid:Grid) =
let underPopulated = grid |> isUnderPopulated
if underPopulated then Dead
else Alive
let grid_1 = { grid with Four= grid |> update };; // Updated here

Answer 1

You may be trying to bind a breakpoint to an application that is out-of-date, meaning that after changes have been made and before they have been recompiled.
Try:
Compile in Debug mode.
Try to Clean Solution before setting the breakpoint.
Go to the Debug folder, and delete [Your application].pdb file.
Then do a Build or Rebuild your application.
Go to the Debug folder and confirm you have a brand new [Your
application].pdb file.
Then try to set your break point.
You may be not be generating Debug information or you may be in optimization mode which could have an effect on this.
For C++ projects:
Check the following project properties:
C++/General/Debug Information Format: Program Database.
C++/Optimization: Disabled.
C++/Code generation/Runtime library: Multi-threaded Debug.
Linker/Debugging/Generate Debug Info: Yes.
Linker/Debugging/Generate program database:
$(TargetDir)$(TargetName).pdb.
Linker/Manifest File/Generate Manifest: No.
Linker/Manifest File/Allow Isolation: No.
Linker/Embedded IDL/Ignore embedded IDL: Yes.
For C# projects check the following:
In the projects properties set Build/General/Optimize code : Disabled.
In the IDE settings Debug/Options/Debug/General Suppress JIT
optimization on module load (Managed only): Enabled
It may be a bug in your VS.
Try opening your solution in another machines IDE. If you can bind a breakpoint on a different machine this can mean that there is an issue with either your VS or your OS..
Check that your IDE is up-to-date:
There have been reports of issues like this in the VS2013 RTM as well as VS2015 Update 1 and Update2.
In VS go to Tools/Extensions & Updates/Updates/Product Updates and see what version you are running. If an update is needed it will appear there.
It may be due to a bug in the OS.
If your running a Win 10 OS, there was a reported bug regarding this issue which existed in build 14251. This was resolved in build 14257 (and above).