Christophe Nasarre

I like this kind of comment: "well... I did not do it on purpose"

Here comes the fifth and final post about spying on AI harnesses: you will see what transcripts files bring; including the system prompts sent to the model! chrisnas.github.io/posts/2026-1...

Techorama Utrecht 2026 is approaching... I've added a few "undocumented corners" to my talk about spying on Copilot, Cursor and Claude ;^) It is still time to register before october 15th and get a 100€ discount by following this link - pretix.eu/techorama-nl.... See you there! #techorama

Just published a new issues of .NET R&D Digest! Thanks to @lemire.bsky.social, @maartenballiauw.be, @andrewlock.bsky.social, @chrisnas.bsky.social, @meziantou.net and other great authors for their amazing content! olegkarasik.wordpress.com/2026/10/02/n... #dotnet

Time to look at Github Copilot in the fourth episode of my long series about AI harnesses internals chrisnas.github.io/posts/2026-0...

Let's turn to Claude this week in the third episode of my long series about AI harnesses internals - chrisnas.github.io/posts/2026-0...

I'm really starting to get scared...

It is time to look at how to rebuild a conversation based on Cursor's hooks with the second episode of my long series about AI harnesses internals - chrisnas.github.io/posts/2026-0...

I'm starting a new series about internals of AI harnesses such as Cursor, Claude or Copilot. Let's start with Cursor that I use everyday chrisnas.github.io/posts/2026-0...

Let's meet in Prague to talk about .NET CLI tools and AI-driven production investigations!

This looks like a very bad reason to close an issue...

I did not know I was doing anything related to cyber security!

Summer is a good time to revisit the old VMMap 2007 sample from Windows via C/C++ book. I've explained the Windows implementation improvements and the Linux port to this new blog post and the source code is available in github.com/chrisnas/ASMap. chrisnas.github.io/posts/2026-0... Happy reading!

New issue of .NET R&D Digest is here! Thx to @lemire.bsky.social, @maartenballiauw.be, @chrisnas.bsky.social, @meziantou.net, @andrewlock.bsky.social & other authors for their g8 content! olegkarasik.wordpress.com/2026/07/02/n... #dotnet

Let's dig into the new cDAC way to access .NET runtime internals :^) chrisnas.github.io/posts/2026-0... Happy reading!

The source code and the slides of my presentation about .NET CLI tools with AI are available from github.com/chrisnas/Buc....

Preparing to talk about .NET CLI tool in our AI fury world at #TechWeekRO #BusinessSummits. See you there!

Moving forward into the cDAC way to access CLR internals...

It is time to use agent for production investigations! See how to leverage .NET CLI tools, MCP servers and skills in my new post

When you mess up with file watcher and git...

Thanks everyone for attending my #UCK26 session! The slides and source code are available from my repo - github.com/chrisnas/Upd...

I was a HUGE fan of Cursor UI and I was forced to update to a new version today so now... it is unusable :^( Maybe it was too easy to have conversation per folder in a sidebar with most of the screen dedicated to plan. Cursor team: please let me use the previous version!!

Finishing to prepare my .NET CLI & AI session for #UCK26: dotnet-pstacks and dotnet-dstrings have been updated to behave as MCP servers with tools and custom prompts. In addition, dedicated SKILL.md files have been added to github.com/chrisnas/Deb.... Happy troubleshooting!

While preparing my session about .NET CLI and AI for #UpdateConference, I just realized that dotnet-dump was downloaded 60+ million times and still growing!

The loneliness of the speaker before his talk @kevingosse.net #Techorama

The content of my #Techorama Belgium talk is available at github.com/chrisnas/Tec...: slides and source code including the Frozen Segment implementation by @kevingosse.net

Even when we don't co-present, @kevingosse.net is able to make me change the slides (and code) of my presentation! See you tomorrow at #Techorama!

I've just added 13 "old" posts to chrisnas.github.io: everything about TraceEvent, counters and the ClrMD series are back on line (Broken links and missing figures from Criteo)!

For my new session about .NET CLI tools and AI, I've updated my own CLI tools to support new versions of .NET in the future (dotnet-wait, dotnet-http, dotnet-gcstats, dotnet-fullgc) and act as MCP server (dotnet-pstacks, dotnet-dstrings) during production investigations Happy troubleshooting!

How to let agents investigate issues with the right SKILL.md.

Blogged: Removing byte[] allocations in .NET Framework using ReadOnlySpan<T> andrewlock.net/removingbyte... In this post I describe how to remove static byte[] allocations, even on .NET Framework, by using Span<T> look at the associated IL, and discuss the potential risks #dotnet

I'm moving from Medium to Github pages! chnasarre.medium.com/aa972d9ff6c6...

Great discussion about "new" async/await in .NET with Andy Gocke from the .NET team! A lot for me to read and dig into the new implementation - github.com/dotnet/runti...

Magical

After DIA and DbgHelp, time to dig into ISymUnmanagedReader to get line and source information from .NET Framework symbols - chnasarre.medium.com/7663f9043b6b...

This is nice: thanks VS!

1h40 de sujets techniques liés aux bons/mauvais usages des strings en .NET avec tout plein de questions pertinentes de @dvoituron.bsky.social, Adrien Clerbois et @peug.net. Les ressources (outils, code source et vidéos) sont aussi disponibles. devapps.ms/podcasts/116...

Why would you need .pdb files for .NET assemblies? Don't their already contain all the needed metadata? This post will show you how to extract the source code and line number information from the .pdb files generated by .NET compilers thanks to DbgHelp API. chnasarre.medium.com/4188f862211d...

I just implemented a tool accepting a .pdb file to generate a .sym file listing functions symbols. A first post (chnasarre.medium.com/9826fd4f251e...) shows the coding details. I'm sharing my vibe coding experience using Cursor in a second longer one (chnasarre.medium.com/f957106a3e9f...)

I spent more time than expected to understand why my .NET profiler never received the event that would help me figuring out the GC mode (Server/Workstation) but Perfview and dotnet-trace did. I needed to debug the CLR to realize that the event is emitted before the profiler gets initialized :^(

And now the profiler is deadlocking the GC :^(

When you realize that the C++ exceptions you get while debugging your complicated profiler code come from... the Windows anti-virus

Venez nous retrouver au DevDay 2025... et avec une ristourne de 20% avec ce code devday.be/ticket?disco... ;^) En plus de venir discuter du "moins mauvais" usage des strings avec moi, beaucoup d'autres présentations sont très intéresantes. A très bientôt !

If you want to recompile the .NET 10 RC2 clr to get a solution for VS2026, you should add "18 2026" to that line of runtime\eng\native\gen-buildsys.cmd. Otherwise the build command will fail

The slides and source code for the two #Techorama sessions (including the duet with @kevingosse.net) are available in github.com/chrisnas/Tec...

Whaaaaaaat!!!! My Astronomy Pix of the day app is broken :^(

Too bad it is not version 11111.11

The 3.28 release of the Datadog .NET profiler supports the new allocations sampling of .NET 10 that allows us to provide a much more statistically accurate view of your application memory! github.com/DataDog/dd-t... Thanks Noah Falk for his help on this ~2 years project :^)

I don't understand how people could use GPTs efficiently... I'm looking for implementation details in the .NET runtime for the generation of gcdump and... ChatGPT and Deepseek are just hallucinating even when I'm pointing them to the current CLR main branch :^(

It is not too late to register to @azuredevsummit! Here is a $200 discount code! Discount code = spkrpromo Registration link = azuredevsummit.com/tickets P.S. Meet there to talk about strings in .NET and maybe win a signed copy of the second edition of Pro .NET Memory ;^)