Step 1: Use the following command in Terminal to find the dSYM on your Mac which build the app
mdfind "com_apple_xcode_dsym_uuids == 12345678-90AB-CDEF-1234-567890ABCDEF"
The string "12345678-90AB-CDEF-1234-567890ABCDEF" is the UUID string from the crash report reformatted to uppercase and 8-4-4-4-12 groups.
Step 2: Symobolicate Crash Report. Excute the following line before symbolicating
Step3: Place your .crash, .app, and .dSYM files in the same directory and run:
/path/symbolicatecrash /path/mycrash.crash /path/MyAppName.app.dSYM > symbolicatedcrash.crash
The path of symbolicatecrash tool in Xcode 9.1 is: /Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/symbolicatecrash, you can check that according to your Xcode version.
TestFlight & Appstore:
If you has enabled Bitcode when you export the ipa via Xcode, the binary will be re-compiled by Apple and create new dSYM for it. You can download the new dSYM file from iTunes Connect or Xcode->Window->Organizer, about this you can refer to this All about Missing dSYMs.