Xcode 9: Could not attach to pid

Question

I\'ve been facing an issue (frequently) with the recent major release of the iOS application development tool - Xcode 9-beta.

It\'s showing me the following error fr

Answer 1

It's an issue with authorization. Try this in the Terminal:

sudo DevToolsSecurity -enable

Answer 2

This worked for me:

Edit Scheme -> Info -> Executable -> Ask on launch

Credits to @nastya-gorban's answer here

Update

After spending a considerable time with examples on Apple bug report, they basically disregarded the issue as using manual certificates is not "expected".

Long story short, if you don't have a business account and hence multiple developers on the same account, you should be fine with using the automatic signing and should not see the issue.

If you do have a business account with multiple users (which I found it breaks automatic signing), this is their suggestion:

We suggest that you use automatic signing for your debug builds and manual signing for your distribution builds.

Answer 3

After doing some digging, this worked for me on Xcode 10.3.

sudo /usr/sbin/DevToolsSecurity -enable

Answer 4

delete derived data and clean the project, wait until processing is complete, this may take some time. The idea is to give some processing time. Works fine after that

Answer 5

Killing my simulator and then running it again from Xcode.

Answer 6

I tried all the answers above. The only thing worked to me is changing the build number.