follow | Very stable , very reliable , NodeJS CouchDB

For me, cleaning and getting the packages didn't work. This error started after I upgraded flutter. I was on the master channel, a quick fix for me was to switch to stable.

You will have to clear the npx cache to make it work.

You can locate the location of the folder where create-react-app is installed using npm ls -g create-react-app.

Also, to clear the cache, refer to this answer in How can I clear the central cache for `npx`?

Issue:

The issue raises after .NET 6 migration. There's a new feature that blocks multiple files from being copied to the same target directory with the same file name. See https://docs.microsoft.com/en-us/dotnet/core/compatibility/sdk/6.0/duplicate-files-in-output

Solution #1 (workaround):

You can add the following build property to all your publishable (*.Web) projects' *.csproj files. This property will bypass this check and works as previously, in .NET5.

WebApplicationBuilder returned by WebApplication.CreateBuilder(args) exposes Configuration and Environment properties:

It's a global outage in JCenter. You can monitor status at https://status.gradle.com. It replaces the bintray status page which seems is now fully sunset and returns a 502 error.

UPDATE Jan 13, 06:35 UTC

JCenter is now back online, and systems are fully operational.

UPDATE Jan 20

Gradle Plugin resolution outage postmortem

https://blog.gradle.org/plugins-jcenter

Following this incident, the Gradle Plugin Portal now uses a JCenter mirror hosted by Gradle instead of JCenter directly. This should shield users from short JCenter outages for libraries that have been cached by the mirror. We saw another short outage of JCenter over the weekend and this did not appear to impact Gradle Plugin Portal users.

It does not default to zero. The sample answer is wrong. Undefined behaviour is undefined; the value may be 0, it may be 100. Accessing it may cause a seg fault, or cause your computer to be formatted.

As to why it's not an error, it's because C++ is not required to do bounds checking on arrays. You could use a vector and use the at function, which throws exceptions if you go outside the bounds, but arrays do not.

When exactly does segmentation fault happen (=when is SIGSEGV sent)?

When you attempt to access memory you don’t have access to, such as accessing an array out of bounds or dereferencing an invalid pointer. The signal SIGSEGV is standardized but different OS might implement it differently. "Segmentation fault" is mainly a term used in *nix systems, Windows calls it "access violation".

Why is the process in undefined behavior state after that point?

Because one or several of the variables in the program didn’t behave as expected. Let’s say you have some array that is supposed to store a number of values, but you didn’t allocate enough room for all them. So only those you allocated room for get written correctly, and the rest written out of bounds of the array can hold any values. How exactly is the OS to know how critical those out of bounds values are for your application to function? It knows nothing of their purpose.

Furthermore, writing outside allowed memory can often corrupt other unrelated variables, which is obviously dangerous and can cause any random behavior. Such bugs are often hard to track down. Stack overflows for example are such segmentation faults prone to overwrite adjacent variables, unless the error was caught by protection mechanisms.

If we look at the behavior of "bare metal" microcontroller systems without any OS and no virtual memory features, just raw physical memory - they will just silently do exactly as told - for example, overwriting unrelated variables and keep on going. Which in turn could cause disastrous behavior in case the application is mission-critical.

Why is it not recoverable?

Because the OS doesn’t know what your program is supposed to be doing.

Though in the "bare metal" scenario above, the system might be smart enough to place itself in a safe mode and keep going. Critical applications such as automotive and med-tech aren’t allowed to just stop or reset, as that in itself might be dangerous. They will rather try to "limp home" with limited functionality.

Why does this solution avoid that unrecoverable state? Does it even?

That solution is just ignoring the error and keeps on going. It doesn’t fix the problem that caused it. It’s a very dirty patch and setjmp/longjmp in general are very dangerous functions that should be avoided for any purpose.

We have to realize that a segmentation fault is a symptom of a bug, not the cause.

Cache misses. When N int objects are allocated back-to-back, the memory reserved to hold them tends to be in a contiguous chunk. So crawling over the list in allocation order tends to access the memory holding the ints' values in sequential, contiguous, increasing order too.

Shuffle it, and the access pattern when crawling over the list is randomized too. Cache misses abound, provided there are enough different int objects that they don't all fit in cache.

At r==1, and r==2, CPython happens to treat such small ints as singletons, so, e.g., despite that you have 10 million elements in the list, at r==2 it contains only (at most) 100 distinct int objects. All the data for those fit in cache simultaneously.

Beyond that, though, you're likely to get more, and more, and more distinct int objects. Hardware caches become increasingly useless then when the access pattern is random.

Illustrating:

A constraint on the deduced auto type doesn't mean it needs to be a specific type, it means it needs to be one of a set of types that satisfy the constraint. Note that a constraint and a type are not the same thing, and they're not interchangeable.

e.g. a concept like std::integral constrains the deduced type to be an integral type, such as int or long, but not float, or std::string.

If I really need a std::integral datatype, couldn't I just omit the auto completely?

In principle, I suppose you could, but this would at the minimum lead to parsing difficulties. e.g. in a declaration like