I have an F# Azure Function that is failing, in a bizarre way, and don't know how to approach fixing the issue. I created a minimum repro of the actual case below. The test function is manually triggered and uses FSharp.Compiler.Service as a dependency, as specified in the project.json below:
{
"frameworks": {
"net46":{
"dependencies": {
"FSharp.Compiler.Service": "11.0.6"
}
}
}
}
The run.fsx file looks like this:
open System
open Microsoft.FSharp.Compiler
open Microsoft.FSharp.Compiler.Ast
open Microsoft.FSharp.Compiler.Interactive.Shell
let Run(input: string, log: TraceWriter) =
// code here that uses FsiEvaluationSession
// and runs just fine
log.Info "I RAN"
So far, so good. The part that baffles me is that if I add the following function above Run,
// same dependencies as before
open Microsoft.FSharp.Compiler.Interactive.Shell
let foo (longIdent:LongIdent) =
// version 1
// "FOO"
// version 2
// longIdent.ToString ()
// version 3
longIdent |> List.map string
let Run(input: string, log: TraceWriter) =
// same as before
Uncommenting section 1 alone works fine, uncommenting section 2 alone works fine, uncommenting section 3 causes hell to break loose. The function compiles, but running it causes the following exception:
Exception while executing function: Functions.fsc-1. mscorlib: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
... which is puzzling to me, because
foo isn't even called anywhere
the signature and the 2nd version both use LongIdent, so this type doesn't seem to be the source of the problem.
Any suggestion on how to approach the problem, and what the problem itself might be, would be very appreciated - I don't even know where to start, and the same code runs perfectly fine in a local script.
I believe the reason for this is that Azure Functions SDK depend on FSharp.Compiler.Service (FCS) version 9.0.1. This means that when you try to load a different version of FCS, you will get the already loaded version 9.0.1.
This works as long as the public API of the FCS version you are using matches the public API of version 9.0.1, but when there are differences, it will crash, because your code assumes that the public API looks different. I suppose this might be triggering the issue here, although I'm not 100% sure how (possibly, LongIdent is now a different thing than it was in version 9.0.1?)
The very same issue used to happen with FAKE, which also bundles FCS and prevented loading of different versions. One of the options is to rename the assembly to avoid the clash.
I also got the same error, I solved it by doing the following workaround, please refer if it works for you also.
Right-click on the Project and select properties.
Goto Debug tab and create a profile with the reference to the below
screenshot.
Note: Replace UserName with your username.
Related
I want to use VSC to develop some extensions to an existing project. In particular UglifyJS3.
So I create a test script, in which I call into the module to test and debug my changes. The code there is simply:
var UglifyJS = require("../tools/node");
var result = UglifyJS.minify(code, ...)
This works while debugging/single-stepping. However VSC already fails to resolve the minify function which is exported by UglifyJS.
I am also not able to simply set breakpoints in the UglifyJS files and have them triggered. VSC shows an error on startup about not being able to resolve the breakpoint.
Looking at ../tools/node.js I see code like:
var UglifyJS = exports;
require.resolve("../lib/utils.js")
...
require.resolve("../lib/minify.js")
require.resolve("./exports.js")
with exports.js containing exports["minify"] = minify;.
Is there anything I have missed? How can I make debugging (and optionally IntelliSense) work?
I found the reason:
First clue was that the code showed up in the debugger as <eval> and in a VM<some number> tab. So somehow the code was not actually read from file but dynamically evaluated.
What happens is (to a reduced example):
var fn = require.resolve("<file>"); // Resolve the filename
var code = fs.readFileSync(fn, "utf8");; // Read the file contents
new Function("exports", code)(exports); // Create a new function containing the files code and execute it
The last bit is a bit more cryptic in code and the new Function was new to me (no pun intended). It essentially boils down to an optimized eval with strict-mode compatibility: https://whereswalden.com/2011/01/10/new-es5-strict-mode-support-new-vars-created-by-strict-mode-eval-code-are-local-to-that-code-only/
Hence: The code executed is actually eval'd code and not the files itself.
Solution: Either live with it or change it upstream to "clean" modules.
I decided to start a new project to get into hacklang, and after fixing some if the problems I initially ran into transitioning from php habits, I ran into the following errors:
Unbound name: str_replace
Unbound name: empty
Doing some research I found that this is due to using 'legacy' php which isn't typechecked, and will error with //strict.
That's fine and all, empty() was easy enough to replace, however str_replace() is a bit more difficult.
Is there an equivalent function that will work with //strict? Or at least something similar.
I'm aware that I could use //decl but I feel like that defeats the purpose in my case.
Is there at least any way to tell which functions are implemented in hack and which are not in the documentation as I couldn't find one?
For reference (though it isn't too relevant to the question itself), here is the code:
<?hh //strict
class HackMarkdown {
public function parse(string $content) : string {
if($content===null){
throw new RuntimeException('Empty Content');
}
$prepared = $this->prepare($content);
}
private function prepare(string $contentpre) : Vector<string>{
$contentpre = str_replace(array("\r\n","\r"),"\n",$contentpre);
//probably need more in here
$prepared = Vector::fromArray(explode($contentpre,"\n"));
//and here
return $prepared;
}
}
You don't need to change your code at all. You just need to tell the Hack tools about all the inbuilt PHP functions.
The easiest way to do this is to download this folder and put it somewhere in your project. I put it in a hhi folder in the base of my project. The files in there tell Hack about all the inbuilt PHP functions.
Most of them don't have type hints, which can lead to Hack thinking the return type of everything is mixed instead of the actual return, that is actually correct in most cases as, for example, str_replace can return either a string or a bool. However, it does stop the "unbound name" errors, which is the main reason for adding them.
I am running my application in VS2012 and I am getting a runtime error;
When I look in the "Original Location" I see mscorlib.dll, but not mscorlib.pdb.
Why is this happening and how do I fix it?
Goto Tools, Options, Debugging, General, Enable Just My Code
This will prevent the debugger from trying to launch on a Internal .NET Framework Assembly.
Goto Tools, Options, Debugging, Symbols and set a cache location. Then hit load in the above and it will fetch the necesary symbols for you and store them in the cache location you provide.
Microsoft's compiler tools create symbols in separate files with a .pdb extension (program database). This allows them to create detached symbols for release binaries. With a symbol server, your IDE can fetch the symbol file matching the specific version of the DLL during debugging. You can configure this system for your own product binaries as well which can be very useful for post-mortem debugging any crashes on end-user machines.
See Microsoft's documentation for more details about using their public symbols.
I had this issue when I was using a static variable, whose value is assigned off a static method.
So, whenever I ran the application, this line of code threw exception. If you place a debug point on this (like I did), you will notice the exception being thrown.
The best Solution to solve this error is:
1: Open App.config file.
2: Paste this useLegacyV2RuntimeActivationPolicy="true" code in the startup tag.
3: Save it.
Now the error would disappear.
Moreover see Image. I have done this for you.
This happened to me for a different reason: I had referenced an old version of NLog (2.0) and needed to reference version 4.0, instead.
In a VB console app, in my case it was none of the above.
Just doing a string calculation in the Dim declarations before my subs.
The offending code:
Dim FylPrefix$ = Fyl.Substring(0, Fyl.LastIndexOf("."))
Moving this calculation into the sub it was needed in fixed it! GERONIMO!!
This can happen when you initialize a variable in your class declarations and that initialization throws an exception:
class Program
{
static OracleConnection ora = getOracleConnection();
}
static void main(string[] args)
{
ora.Open();
}
static OracleConnection getOracleConnection()
{
OracleConnection orax = new OracleConnection(description=(host=myHost)
(port=1521)(protocol=tcp))(connect_data=(sid=mySid)));user id=user;password=pw;
}
If an exception is thrown by getOracleConnection() you can get this error. Move your assignment (but not necessarily your declaration) inside of main (where it belongs anyway), and you will get the actual exception that is causing the error instead of the mscorlib error.
In my case the exception began to appear after I changed the "Assembly name" in the "Application" tab of the properties window. If that's the case with you try reverting to the original name and see if the exception disappears.
Perhaps the reason for this was that the new name did not match the AssemblyTitle in AssemblyInfo.cs.
if you have this type of project runtime error in visualstudio
Answer:Cntr+Alt+E open Exception window Uncheck All chechboxes
Must and shoud its working written by B sriram Mca Giet College
rajahmundry, east godavary ,2014 batch
I have referenced jquery.d.ts in my TypeScript Project in Visual Studio 2012 and am getting the following error:
Error 1 Duplicate identifier
'nodeName' C:\DEV\MyProject\Scripts\JQuery\jquery.d.ts 786 2 pageMain.ts
Which leads to the following code in jquery.d.ts:
interface EventTarget {
nodeName: string;
}
I have restarted VS2012, and then again after deleting all the .sou files for the project.
I have checked all my references (includes) and found no other reference to EventTarget.
I have looked in lib.d.ts, and indeed, there is a EventTarget interface, but it does not implement nodeName.
FYI: I found two copies of lib.d.ts on my machine, and checked them both: does anyone know which one is used by the compiler? I did mods on both (changing the window.alert to window.alert2), but they had no effect.
Your jQuery.d.ts needs to be updated.
Here is a quick way to test the issue:
declare var x: EventTarget;
x.nodeName = '';
If you run this on the TypeScript Playground, you'll see that nodeName does not exist on EventTarget. Indeed, if you look at the lib.d.ts file, you'll find this:
interface EventTarget {
removeEventListener(type: string, listener: EventListener, useCapture?: bool): void;
addEventListener(type: string, listener: EventListener, useCapture?: bool): void;
dispatchEvent(evt: Event): bool;
}
However, if you run the same code within Visual Studio with Web Essentials, you'll find that nodeName does exist on EventTarget. This is because Web Essentials is using a newer version of lib.d.ts - if you disable Web Essentials, you would get the same error as you see in the Playground.
These issues will happen occasionally as the standard definitions are improved to keep up with what browsers actually support. Your definition files should be adjusted to keep in line with your development tools, with a preference to changing files such as jquery.d.ts rather than lib.d.ts.
Interesting bug, I faced same issue with className instead of nodeName
After spending sometime trying to solve the issue I found this article link in jquery.d.ts file
I am maintaining general.d.ts file to create required interface items needed.
I added the following definition to the file
interface EventTarget {
className: string;
}
Immediately I got an error message of duplicate identifier.
I kept it and saved general.d.ts, and went back to my original working file, I found the compiler passed through.
My assumption it is Web Essentials bug failing to load definitions properly.
Since I don't know exactly what part of it alone that triggers the error, I'm not entirely sure how to better label it.
This question is a by-product of the SO question c# code seems to get optimized in an invalid way such that an object value becomes null, which I attempted to help Gary with yesterday evening. He was the one that found out that there was a problem, I've just reduced the problem to a simpler project, and want verification before I go further with it, hence this question here.
I'll post a note on Microsoft Connect if others can verify that they too get this problem, and of course I hope that either Jon, Mads or Eric will take a look at it as well :)
It involves:
3 projects, 2 of which are class libraries, one of which is a console program (this last one isn't needed to reproduce the problem, but just executing this shows the problem, whereas you need to use reflector and look at the compiled code if you don't add it)
Incomplete references and type inference
Generics
The code is available here: code repository.
I'll post a description below of how to make the projects if you rather want to get your hands dirty.
The problem exhibits itself by producing an invalid cast in a method call, before returning a simple generic list, casting it to something strange before returning it. The original code ended up with a cast to a boolean, yes, a boolean. The compiler added a cast from a List<SomeEntityObject> to a boolean, before returning the result, and the method signature said that it would return a List<SomeEntityObject>. This in turn leads to odd problems at runtime, everything from the result of the method call being considered "optimized away" (the original question), or a crash with either BadImageFormatException or InvalidProgramException or one of the similar exceptions.
During my work to reproduce this, I've seen a cast to void[], and the current version of my code now casts to a TypedReference. In one case, Reflector crashes so most likely the code was beyond hope in that case. Your mileage might vary.
Here's what to do to reproduce it:
Note: There is likely that there are more minimal forms that will reproduce the problem, but moving all the code to just one project made it go away. Removing the generics from the classes also makes the problem go away. The code below reproduces the problem each time for me, so I'm leaving it as is.
I apologize for the escaped html characters in the code below, this is Markdown playing a trick on me, if anyone knows how I can rectify it, please let me know, or just edit the question
Create a new Visual Studio 2010 solution containing a console application, for .NET 4.0
Add two new projects, both class libraries, also .NET 4.0 (I'm going to assume they're named ClassLibrary1 and ClassLibrary2)
Adjust all the projects to use the full .NET 4.0 runtime, not just the client profile
Add a reference in the console project to ClassLibrary2
Add a reference in ClassLibrary2 to ClassLibrary 1
Remove the two Class1.cs files that was added by default to the class libraries
In ClassLibrary1, add a reference to System.Runtime.Caching
Add a new file to ClassLibrary1, call it DummyCache.cs, and paste in the following code:
using System;
using System.Collections.Generic;
using System.Runtime.Caching;
namespace ClassLibrary1
{
public class DummyCache<TModel> where TModel : new()
{
public void TriggerMethod<T>()
{
}
// Try commenting this out, note that it is never called!
public void TriggerMethod<T>(T value, CacheItemPolicy policy)
{
}
public CacheItemPolicy GetDefaultCacheItemPolicy()
{
return null;
}
public CacheItemPolicy GetDefaultCacheItemPolicy(IEnumerable<string> dependentKeys, bool createInsertDependency = false)
{
return null;
}
}
}
Add a new file to ClassLibrary2, call it Dummy.cs and paste in the following code:
using System;
using System.Collections.Generic;
using ClassLibrary1;
namespace ClassLibrary2
{
public class Dummy
{
private DummyCache<Dummy> Cache { get; set; }
public void TryCommentingMeOut()
{
Cache.TriggerMethod<Dummy>();
}
public List<Dummy> GetDummies()
{
var policy = Cache.GetDefaultCacheItemPolicy();
return new List<Dummy>();
}
}
}
Paste in the following code in Program.cs in the console project:
using System;
using System.Collections.Generic;
using ClassLibrary2;
namespace ConsoleApplication23
{
class Program
{
static void Main(string[] args)
{
Dummy dummy = new Dummy();
// This will crash with InvalidProgramException
// or BadImageFormatException, or a similar exception
List<Dummy> dummies = dummy.GetDummies();
}
}
}
Build, and ensure there are no compiler errors
Now try running the program. This should crash with one of the more horrible exceptions. I've seen both InvalidProgramException and BadImageFormatException, depending on what the cast ended up as
Look at the generated code of Dummy.GetDummies in Reflector. The source code looks like this:
public List<Dummy> GetDummies()
{
var policy = Cache.GetDefaultCacheItemPolicy();
return new List<Dummy>();
}
however reflector says (for me, it might differ in which cast it chose for you, and in one case Reflector even crashed):
public List<Dummy> GetDummies()
{
List<Dummy> policy = (List<Dummy>)this.Cache.GetDefaultCacheItemPolicy();
TypedReference CS$1$0000 = (TypedReference) new List<Dummy>();
return (List<Dummy>) CS$1$0000;
}
Now, here's a couple of odd things, the above crash/invalid code aside:
Library2, which has Dummy.GetDummies, performs a call to get the default cache policy on the class from Library1. It uses type inference var policy = ..., and the result is an CacheItemPolicy object (null in the code, but type is important).
However, ClassLibrary2 does not have a reference to System.Runtime.Caching, so it should not compile.
And indeed, if you comment out the method in Dummy that is named TryCommentingMeOut, you get:
The type 'System.Runtime.Caching.CacheItemPolicy' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
Why having this method present makes the compiler happy I don't know, and I don't even know if this is linked to the current problem or not. Perhaps it is a second bug.
There is a similar method in DummyCache, if you restore the method in Dummy, so that the code again compiles, and then comment out the method in DummyCache that has the "Try commenting this out" comment above it, you get the same compiler error
OK, I downloaded your code and can confirm the problem as described.
I have not done any extensive tinkering with this, but when I run & reflector a Release build all seems OK (= null ref exception and clean disassembly).
Reflector (6.10.11) crashed on the Debug builds.
One more experiment: I wondered about the use of CacheItemPolicies so I replaced it with my own MyCacheItemPolicy (in a 3rd classlib) and the same BadImageFormat exception pops up.
The exception mentions : {"Bad binary signature. (Exception from HRESULT: 0x80131192)"}