Git: Text expressions have no return value because there is no git repo.

Description

I think all VCS text expressions should return unknown if there is no Git repo to avoid misunderstandings.

Bildschirmfoto vom 2026-02-14 14-49-02.png

Otherwise, it is not possible for the user to distinguish between fields that have not been filled in or have been filled in incorrectly and Git repos that do not exist.

Steps to reproduce

  1. Create a new project
  2. Create an schematic
  3. Insert an text item with e.g. Hash: @{vcsidentifier(8)}@{vcsdirtysuffix("-dirty")}

KiCad Version 

Application: KiCad Schematic Editor x86_64 on x86_64

Version: 10.0.0-rc1-1.20260212gitdd4c517.fc42, release build

Libraries:
	wxWidgets 3.2.8
	FreeType 2.13.3
	HarfBuzz 10.4.0
	FontConfig 2.16.0
	libcurl/8.11.1 OpenSSL/3.2.6 zlib/1.3.1.zlib-ng libidn2/2.3.8 nghttp2/1.64.0

Platform: Fedora Linux 42 (Workstation Edition), 64 bit, Little endian, wxGTK, X11, gnome-xorg, x11
OpenGL: NVIDIA Corporation, NVIDIA GeForce RTX 3070/PCIe/SSE2, 4.6.0 NVIDIA 580.126.09

Build Info:
	Date: Feb 12 2026 19:22:08
	wxWidgets: 3.2.8 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.83.0
	OCC: 7.8.1
	Curl: 8.11.1
	ngspice: 45.2
	Compiler: GCC 15.2.1 with C++ ABI 1020
	KICAD_IPC_API=ON
	KICAD_USE_PCH=OFF

Locale: 
	Lang: en_GB
	Enc: UTF-8
	Num: 1,234.5
	Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)