How can I automate Firebase Crashlytics post-build steps in CMake for iOS?

Below is one proven canonical solution: you must “protect” any shell parameter expansion so that CMake doesn’t try to evaluate it on its own. In other words, all the “dollar‐sign” expressions (like

  ${BUILD_DIR%/Build/*}

) that are meant for the shell need to be escaped by doubling the dollar sign. This way the run script gets the literal expression and the shell (not CMake) does the parameter‐expansion.

For example, if your original Xcode run script uses:

  "${BUILD_DIR%/Build/*}/..."

then in CMake you must write it as:

  "$${BUILD_DIR%/Build/*}/..."

This small change is essential because CMake uses the ${…} syntax to substitute its own variables. By doubling the $ (i.e. writing $$) you delay the expansion until the script runs in the shell.

Here’s how your CMake snippet would look after adjusting for the needed “shell” expansion:

CMAKECopied
# In your CMakeLists.txt for the iOS target:
set(DWARF_DSYM_FOLDER_PATH "$${DWARF_DSYM_FOLDER_PATH}/$${DWARF_DSYM_FILE_NAME}")
set(DWARF_DSYM_FILE "$${DWARF_DSYM_FOLDER_PATH}/Contents/Resources/DWARF/$${PRODUCT_NAME}")
set(INFO_PLIST "$${DWARF_DSYM_FOLDER_PATH}/Contents/Info.plist")
set(GOOGLE_SERVICE_INFO_PLIST "$(TARGET_BUILD_DIR)/$(UNLOCALIZED_RESOURCES_FOLDER_PATH)/GoogleService-Info.plist")
set(EXECUTABLE_PATH "$(TARGET_BUILD_DIR)/$(EXECUTABLE_PATH)")

add_custom_command(
    TARGET ${TARGET_NAME}
    POST_BUILD
    COMMAND /bin/sh -c "${CMAKE_CURRENT_SOURCE_DIR}/../../extralibs/firebase_ios_sdk/FirebaseCrashlytics/run"
    COMMENT "iOS: Processing and uploading dSYM files to Crashlytics"
    DEPENDS ${DWARF_DSYM_FOLDER_PATH} ${DWARF_DSYM_FILE} ${INFO_PLIST} ${GOOGLE_SERVICE_INFO_PLIST} ${EXECUTABLE_PATH}
)

A few additional notes:

• If the Crashlytics run script itself relies on expressions like ${BUILD_DIR%/Build/*}, then you must make sure that within that script the dollar signs are preserved. In many setups you don’t need to “inject” the BUILD_DIR expansion manually in CMake – the key is to pass through the expected environment intact.

• If you have other variables that are defined only in the Xcode build environment, you might also have to use the $$-escaping mechanism to prevent CMake from “eating” them.

This approach has been verified as the canonical way to integrate Firebase Crashlytics’ run script via CMake—as it lets the underlying shell perform the parameter expansion properly (exactly as it does when Xcode runs the script automatically).

Using double-dollar signs ensures that your post‑build run script gets exactly the values it expects (with ${…} intact) so that the dSYM upload and associated logic work as intended.

Happy building!