meson: Error out if fail to extracted version number

.travis.yml

@@ -190,13 +190,13 @@ matrix:
             && python3 ~/get-pip.py --user
             && pip3 install --user meson
       script:
-        - meson --buildtype=debug
+        - meson setup --buildtype=debug
                 -Db_lundef=false
                 -Dauto_features=enabled
                 -Dbuild_{programs,tests,contrib}=true
                 -Ddefault_library=both
                 build/meson builddir
-        - cd builddir
+        - pushd builddir
         - DESTDIR=./staging ninja install
         - tree ./staging
   allow_failures:

build/meson/meson.build

@@ -16,9 +16,7 @@ project('zstd',
     'cpp_std=c++11',
     'buildtype=release'
   ],
-  # Fall-back version in case of extracting version number from
+  version: 'DUMMY',
-  # `zstd.h` failed.
-  version: '1.4.0',
   meson_version: '>=0.47.0')
 
 cc = meson.get_compiler('c')
@@ -45,13 +43,10 @@ zstd_h_file = join_paths(meson.current_source_dir(), '../../lib/zstd.h')
 GetZstdLibraryVersion_py = files('GetZstdLibraryVersion.py')
 r = run_command(python3, GetZstdLibraryVersion_py, zstd_h_file)
 if r.returncode() == 0
-  output = r.stdout().strip()
+  zstd_version = r.stdout().strip()
-  if output.version_compare('>@0@'.format(zstd_version))
+  message('Project version is now: @0@'.format(zstd_version))
-    zstd_version = output
-    message('Project version is now: @0@'.format(zstd_version))
-  endif
 else
-  message('Cannot find project version in @0@'.format(zstd_h_file))
+  error('Cannot find project version in @0@'.format(zstd_h_file))
 endif
 
 zstd_libversion = zstd_version