build: always use the project version

Don't use the latest tag, always use the project version for the version
string. Because of version branches, getting the version from Git can be
unreliable.

Closes: #4631

meson.build

@@ -54,7 +54,6 @@ elogind        = dependency('libelogind', version: '>=239', required: false)
 xcb            = dependency('xcb', required: get_option('xwayland'))
 math           = cc.find_library('m')
 rt             = cc.find_library('rt')
-git            = find_program('git', native: true, required: false)
 
 # Try first to find wlroots as a subproject, then as a system dependency
 wlroots_version = ['>=0.8.1', '<0.9.0']
@@ -130,11 +129,16 @@ endif
 add_project_arguments('-DSYSCONFDIR="/@0@"'.format(join_paths(prefix, sysconfdir)), language : 'c')
 
 version = '"@0@"'.format(meson.project_version())
+git = find_program('git', native: true, required: false)
 if git.found()
-	git_commit_hash = run_command([git.path(), 'describe', '--always', '--tags'])
-	git_branch = run_command([git.path(), 'rev-parse', '--abbrev-ref', 'HEAD'])
-	if git_commit_hash.returncode() == 0 and git_branch.returncode() == 0
-		version = '"@0@ (" __DATE__ ", branch \'@1@\')"'.format(git_commit_hash.stdout().strip(), git_branch.stdout().strip())
+	git_commit = run_command([git, 'rev-parse', '--short', 'HEAD'])
+	git_branch = run_command([git, 'rev-parse', '--abbrev-ref', 'HEAD'])
+	if git_commit.returncode() == 0 and git_branch.returncode() == 0
+		version = '"@0@-@1@ (" __DATE__ ", branch \'@2@\')"'.format(
+			meson.project_version(),
+			git_commit.stdout().strip(),
+			git_branch.stdout().strip(),
+		)
 	endif
 endif
 add_project_arguments('-DSWAY_VERSION=@0@'.format(version), language: 'c')