fix conditional building of sage docs

[dimpase]

Currently we have html docs built unconditionally by make, which triggers a meson slowdown due to dependencies between docs being too "eager".

This is triggered by the line subdir('doc') in src/meson.build. This should be conditional on
a meson option. (and this meson option should also be possible to invoke from ./configure)

We have broken optional packages sagemath_doc_html and sagemath_doc_pdf which were meant to control conditional docbuild (maybe?). (One needs to add a disabler for docbuild as soon as --disable-sagemath_doc_html is given to ./configure)

[antonio-rojas]

There already is a meson option https://github.com/sagemath/sage/blob/10.8.beta8/src/doc/meson.build#L1-3

[dimpase]

@antonio-rojas - does this prevent computing doc dependencies ?

How would I check?

[antonio-rojas]

Run meson with -Dbuild-docs=false, check that it generates 580 build targets instead of 1685 (and it takes a few seconds instead of 5 minutes)

[enriqueartal]

If one is still using ./configure and make, is there an option for this? When building sagelib it also takes 5 minutes for preparation.

[dimpase]

If one is still using ./configure and make, is there an option for this? When building sagelib it also takes 5 minutes for preparation.

there is no option, and that's exactly the problem.
./configure --disable-sagemath_doc_html ... should trigger

--- a/build/pkgs/sagelib/spkg-install.in
+++ b/build/pkgs/sagelib/spkg-install.in
@@ -44,7 +44,7 @@ SITEPACKAGESDIR=$(python3 -c 'import sysconfig; print(sysconfig.get_paths()["pur
 # does not shadow the namespace package sage during the build.
 (cd "$SITEPACKAGESDIR" && rm -f sage/__init__.py)
 if [ "$SAGE_EDITABLE" = yes ]; then
-    sdh_pip_editable_install . --config-settings=build-dir="build/sage-distro" --config-settings=setup-args="-DSAGE_LOCAL=$SAGE_LOCAL"
+    sdh_pip_editable_install . --config-settings=build-dir="build/sage-distro" --config-settings=setup-args="-DSAGE_LOCAL=$SAGE_LOCAL" --config-settings=setup-args="-Dbuild-docs=false"
 
     if [ "$SAGE_WHEELS" = yes ]; then
         # Additionally build a wheel (for use in other venvs)

(and a similar for the non-editable install)

I'll fix this.

[dimpase]

Run meson with -Dbuild-docs=false, check that it generates 580 build targets instead of 1685 (and it takes a few seconds instead of 5 minutes)

Thanks! This worked (see the diff above)