tectonic: --inherit-argv0 in the wrapper

The `nextonic` symlink was not working as intended because our tectonic
wrapper did not correctly pass along the executable name. This is fixed
by adding --inherit-argv0 to `makeWrapper`.

A test is also added to prevent breakage in the future.

pkgs/tools/typesetting/tectonic/tests.nix

@@ -90,4 +90,10 @@ lib.mapAttrs networkRequiringTestPkg {
     tectonic -X new
     cat Tectonic.toml | grep "${tectonic.bundleUrl}"
   '';
+
+  /** test that the `nextonic -> tectonic` symlink is working as intended */
+  nextonic = ''
+    nextonic new 2>&1 \
+      | grep '"version 2" Tectonic command-line interface activated'
+  '';
 }

pkgs/tools/typesetting/tectonic/wrapper.nix

@@ -46,7 +46,8 @@ symlinkJoin {
   + ''
     makeWrapper ${lib.getBin tectonic-unwrapped}/bin/tectonic $out/bin/tectonic \
       --prefix PATH : "${lib.getBin biber-for-tectonic}/bin" \
-      --add-flags "--web-bundle ${tectonic.passthru.bundleUrl}"
+      --add-flags "--web-bundle ${tectonic.passthru.bundleUrl}" \
+      --inherit-argv0 ## make sure binary name e.g. `nextonic` is passed along
     ln -s $out/bin/tectonic $out/bin/nextonic
   '';