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.NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729

Closed
Closed
.NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
Assignees
janvorli
Labels
area-Diagnostics-coreclr
Milestone
9.0.0

Description

@gregg-miskelly
gregg-miskelly
opened on Apr 30, 2024

Description

In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.

Reproduction Steps

  1. dotnet new console
  2. Replace program.cs with the following code
  3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
  4. The debugger will stop when the exception goes unhandled

Program.cs:

Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();

Expected behavior

Call stack should have a managed frame

Actual behavior

No managed frames

Regression?

Definitely a regression from .NET 8. I believe it first appeared in preview 3.

Known Workarounds

None

Configuration

Problem appears on Windows, Mac and Linux

Other information

No response

Metadata

Metadata

Assignees

Labels

area-Diagnostics-coreclr

Type

No type

Projects

No projects

    Milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions

    , 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
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(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
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btn.textContent = 'Copy';
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btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
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addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
    Skip to content
    .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
    Closed
    Closed
    .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
    Assignees
    janvorli
    Labels
    area-Diagnostics-coreclr
    Milestone
    9.0.0
    Description
    @gregg-miskelly
    gregg-miskelly
    opened on Apr 30, 2024
    Description
    In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
    Reproduction Steps
    1. dotnet new console
    2. Replace program.cs with the following code
    3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
    4. The debugger will stop when the exception goes unhandled
    Program.cs:
    Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
    Expected behavior
    Call stack should have a managed frame
    Actual behavior
    No managed frames
    Regression?
    Definitely a regression from .NET 8. I believe it first appeared in preview 3.
    Known Workarounds
    None
    Configuration
    Problem appears on Windows, Mac and Linux
    Other information
    No response
    Metadata
    Metadata
    Assignees
    Labels
    area-Diagnostics-coreclr
    Type
    No type
    Projects
    No projects
      Milestone
      Relationships
      None yet
      Development
      No branches or pull requests
      Issue actions
      
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
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var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
      Skip to content
      .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
      Closed
      Closed
      .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
      Assignees
      janvorli
      Labels
      area-Diagnostics-coreclr
      Milestone
      9.0.0
      Description
      @gregg-miskelly
      gregg-miskelly
      opened on Apr 30, 2024
      Description
      In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
      Reproduction Steps
      1. dotnet new console
      2. Replace program.cs with the following code
      3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
      4. The debugger will stop when the exception goes unhandled
      Program.cs:
      Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
      Expected behavior
      Call stack should have a managed frame
      Actual behavior
      No managed frames
      Regression?
      Definitely a regression from .NET 8. I believe it first appeared in preview 3.
      Known Workarounds
      None
      Configuration
      Problem appears on Windows, Mac and Linux
      Other information
      No response
      Metadata
      Metadata
      Assignees
      Labels
      area-Diagnostics-coreclr
      Type
      No type
      Projects
      No projects
        Milestone
        Relationships
        None yet
        Development
        No branches or pull requests
        Issue actions
        
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
        Skip to content
        .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
        Closed
        Closed
        .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
        Assignees
        janvorli
        Labels
        area-Diagnostics-coreclr
        Milestone
        9.0.0
        Description
        @gregg-miskelly
        gregg-miskelly
        opened on Apr 30, 2024
        Description
        In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
        Reproduction Steps
        1. dotnet new console
        2. Replace program.cs with the following code
        3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
        4. The debugger will stop when the exception goes unhandled
        Program.cs:
        Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
        Expected behavior
        Call stack should have a managed frame
        Actual behavior
        No managed frames
        Regression?
        Definitely a regression from .NET 8. I believe it first appeared in preview 3.
        Known Workarounds
        None
        Configuration
        Problem appears on Windows, Mac and Linux
        Other information
        No response
        Metadata
        Metadata
        Assignees
        Labels
        area-Diagnostics-coreclr
        Type
        No type
        Projects
        No projects
          Milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
          Skip to content
          .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
          Closed
          Closed
          .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
          Assignees
          janvorli
          Labels
          area-Diagnostics-coreclr
          Milestone
          9.0.0
          Description
          @gregg-miskelly
          gregg-miskelly
          opened on Apr 30, 2024
          Description
          In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
          Reproduction Steps
          1. dotnet new console
          2. Replace program.cs with the following code
          3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
          4. The debugger will stop when the exception goes unhandled
          Program.cs:
          Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
          Expected behavior
          Call stack should have a managed frame
          Actual behavior
          No managed frames
          Regression?
          Definitely a regression from .NET 8. I believe it first appeared in preview 3.
          Known Workarounds
          None
          Configuration
          Problem appears on Windows, Mac and Linux
          Other information
          No response
          Metadata
          Metadata
          Assignees
          Labels
          area-Diagnostics-coreclr
          Type
          No type
          Projects
          No projects
            Milestone
            Relationships
            None yet
            Development
            No branches or pull requests
            Issue actions
            
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
            Skip to content
            .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
            Closed
            Closed
            .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
            Assignees
            janvorli
            Labels
            area-Diagnostics-coreclr
            Milestone
            9.0.0
            Description
            @gregg-miskelly
            gregg-miskelly
            opened on Apr 30, 2024
            Description
            In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
            Reproduction Steps
            1. dotnet new console
            2. Replace program.cs with the following code
            3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
            4. The debugger will stop when the exception goes unhandled
            Program.cs:
            Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
            Expected behavior
            Call stack should have a managed frame
            Actual behavior
            No managed frames
            Regression?
            Definitely a regression from .NET 8. I believe it first appeared in preview 3.
            Known Workarounds
            None
            Configuration
            Problem appears on Windows, Mac and Linux
            Other information
            No response
            Metadata
            Metadata
            Assignees
            Labels
            area-Diagnostics-coreclr
            Type
            No type
            Projects
            No projects
              Milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
              Skip to content
              .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
              Closed
              Closed
              .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
              Assignees
              janvorli
              Labels
              area-Diagnostics-coreclr
              Milestone
              9.0.0
              Description
              @gregg-miskelly
              gregg-miskelly
              opened on Apr 30, 2024
              Description
              In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
              Reproduction Steps
              1. dotnet new console
              2. Replace program.cs with the following code
              3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
              4. The debugger will stop when the exception goes unhandled
              Program.cs:
              Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
              Expected behavior
              Call stack should have a managed frame
              Actual behavior
              No managed frames
              Regression?
              Definitely a regression from .NET 8. I believe it first appeared in preview 3.
              Known Workarounds
              None
              Configuration
              Problem appears on Windows, Mac and Linux
              Other information
              No response
              Metadata
              Metadata
              Assignees
              Labels
              area-Diagnostics-coreclr
              Type
              No type
              Projects
              No projects
                Milestone
                Relationships
                None yet
                Development
                No branches or pull requests
                Issue actions
                
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
.NET 9: Unhandled exceptions in background threads reported with empty managed frames · Issue #101729 · dotnet/runtime · GitHub
                Skip to content
                .NET 9: Unhandled exceptions in background threads reported with empty managed frames #101729
                Closed
                Closed
                .NET 9: Unhandled exceptions in background threads reported with empty managed frames#101729
                Assignees
                janvorli
                Labels
                area-Diagnostics-coreclr
                Milestone
                9.0.0
                Description
                @gregg-miskelly
                gregg-miskelly
                opened on Apr 30, 2024
                Description
                In .NET 9 preview 3, there is a regression where the target process stops at a point where the ICorDebug stack walk interfaces report a single native chain with reason CHAIN_THREAD_START (0x00000040). Previously these exceptions would go unhandled with the managed code still on the stack.
                Reproduction Steps
                1. dotnet new console
                2. Replace program.cs with the following code
                3. Run it under a managed debugger that is NOT configured to stop when NotImplementedException is thrown
                4. The debugger will stop when the exception goes unhandled
                Program.cs:
                Threadthread=newThread(()=>{thrownewNotImplementedException();// should crash here});thread.Start();thread.Join();
                Expected behavior
                Call stack should have a managed frame
                Actual behavior
                No managed frames
                Regression?
                Definitely a regression from .NET 8. I believe it first appeared in preview 3.
                Known Workarounds
                None
                Configuration
                Problem appears on Windows, Mac and Linux
                Other information
                No response
                Metadata
                Metadata
                Assignees
                Labels
                area-Diagnostics-coreclr
                Type
                No type
                Projects
                No projects
                  Milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions