Fix Makefile.common patch/gsub

[ladislas]

fixes #378

[Copilot]

Pull request overview

This PR fixes the Makefile.common patching logic to work correctly with versioned avr-gcc installations. The change replaces a simple path substitution with a more robust approach that dynamically finds and uses the first matching avr-gcc installation directory.

• Replaces the gsub pattern to search for any avr-gcc* directory in Homebrew's Cellar
• Uses Makefile variables and wildcard expansion instead of shell test commands

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[Copilot]

The gsub! call has inconsistent indentation in the replacement text. The newline character is followed by 3 spaces, but this may not match the indentation in the original Makefile.common file. Incorrect indentation in Makefiles can cause syntax errors or unexpected behavior. Verify the correct indentation level needed in the target file and adjust accordingly.

Suggested change

	s.gsub! "ifneq (${shell test -d $(HOMEBREW_PREFIX)/Cellar/avr-gcc* && echo Exists}, Exists)",
	"AVR_GCC_DIR := $(firstword $(wildcard $(HOMEBREW_PREFIX)/Cellar/avr-gcc*/))\n ifeq ($(AVR_GCC_DIR),)"
	s.gsub!(/^(\s*)ifneq \(\$\{shell test -d \$(HOMEBREW_PREFIX)\/Cellar\/avr-gcc\* && echo Exists\}, Exists\)/,
	"\\1AVR_GCC_DIR := $(firstword $(wildcard $(HOMEBREW_PREFIX)/Cellar/avr-gcc*/))\n\\1ifeq ($(AVR_GCC_DIR),)")

[Copilot]

The search pattern uses ${shell ...} but standard Makefile syntax uses $(shell ...) for command substitution. If the actual Makefile.common file uses $(shell ...) instead of ${shell ...}, this gsub! will not find a match and silently fail to apply the patch. Consider verifying the exact syntax in the source file.

Suggested change

	s.gsub! "ifneq (${shell test -d $(HOMEBREW_PREFIX)/Cellar/avr-gcc* && echo Exists}, Exists)",
	s.gsub! "ifneq ($(shell test -d $(HOMEBREW_PREFIX)/Cellar/avr-gcc* && echo Exists), Exists)",