Allow SAGE_LOCAL to be customized

[jdemeyer]

This ticket allows a $SAGE_LOCAL directory different from $SAGE_ROOT/local.

The idea is that #21479 would set $SAGE_LOCAL to the --prefix chosen by the user.

CC: @mkoeppe

Component: build

Author: Jeroen Demeyer

Branch: 64e697d

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/21501

[sagetrac-felixs]

comment:1

that seems to make sense. but it's dangerous really. SAGE_LOCAL is an internal directory and an implementation detail currently.

if you expose this, users will start expecting stuff in SAGE_LOCAL created by the build process. an ideal build process does not (will not/should not) use SAGE_LOCAL. any transition to fixing this will heavily interfere with user experience (only if they override SAGE_LOCAL, of course).

ok, now i explained why "set prefix==SAGE_LOCAL" is probably not a good idea. and here, an alternative, "expose SAGE_LOCAL", appears to be much worse... hmm

there's a problem here. can you please give some more insight on what you are trying to achieve with the customized SAGE_LOCAL?

thanks

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1 +1,3 @@
-See #21479 for the rationale.
+This ticket allows a `$SAGE_LOCAL` directory different from `$SAGE_ROOT/local`.
+
+The idea is that #21479 would set `$SAGE_LOCAL` to the `--prefix` chosen by the user.

[jdemeyer]

comment:2

Replying to @sagetrac-felixs:

SAGE_LOCAL is an internal directory and an implementation detail currently.

I am not changing that. I still consider it an implementation detail.

can you please give some more insight on what you are trying to achieve with the customized SAGE_LOCAL?

I am allowing Sage to be installed in a custom directory, which is not $SAGE_ROOT/local.

[sagetrac-felixs]

comment:3

I am allowing Sage to be installed in a custom directory,

SAGE_LOCAL cannot be the installation directory and an implementation detail.

but you seem to have your own definition for both these terms, rendering this discussion pointless.

[jdemeyer]

comment:4

Replying to @sagetrac-felixs:

I am allowing Sage to be installed in a custom directory,

SAGE_LOCAL cannot be the installation directory and an implementation detail.

The current reality is that $SAGE_LOCAL is the installation directory and an implementation detail. So I am really not changing that.

[sagetrac-felixs]

comment:5

Replying to @jdemeyer:

The current reality

you put "Allow SAGE_LOCAL to be customized" into the title. this (to me) implies that SAGE_LOCAL would become a user controlled variable (see above). i hope not! but is it really your intent?

i figured, that maybe/actually/hopefully you want to introduce prefix (defaulting to $(builddir)/local), then set SAGE_LOCAL=prefix. then do some modifications so the rest of dist can cope with it.

about the title... what about "implement pretend-prefix using SAGE_LOCAL" or "use SAGE_LOCAL to implement pretend-prefix"? (yes, "pretend", because it will look like prefix to the user, while the build process will still write to it).

[mkoeppe]

comment:6

Jeroen, are you working on this?
Which changes should go into this ticket, and which changes into #21479?

[jdemeyer]

comment:7

Replying to @mkoeppe:

Jeroen, are you working on this?

Yes.

Which changes should go into this ticket, and which changes into #21479?

My idea is that this ticket simply allows SAGE_LOCAL to be set to a different directory and that #21479 implements the ./configure logic to automatically set SAGE_LOCAL to the --prefix given.

[mkoeppe]

comment:8

OK, great. I assume that you can test #21501 separately by just setting an environment variable, so #21501 should be a prereq of #21479, correct?

[jdemeyer]

comment:9

Replying to @mkoeppe:

OK, great. I assume that you can test #21501 separately by just setting an environment variable, so #21501 should be a prereq of #21479, correct?

Yes.

[jdemeyer]

Branch: u/jdemeyer/ticket/21501