#5852: The detection of SAGE_ROOT in $SAGE_ROOT/sage script should expand
symlinks
recursively
-----------------------------+----------------------------------------------
Reporter: tornaria | Owner: tornaria
Type: defect | Status: needs_work
Priority: major | Milestone: sage-4.7.2
Component: distribution | Resolution:
Keywords: | Work_issues:
Upstream: N/A | Reviewer:
Author: | Merged:
Dependencies: |
-----------------------------+----------------------------------------------
Description changed by jdemeyer:
Old description:
> Currently, {{{$SAGE_ROOT/sage}}} uses (first among other alternate
> methods) {{{readlink -n}}} to detect the directory where the script lives
> (that's $SAGE_ROOT), but it should use {{{readlink -nf}}} to expand
> symlinks recursively.
>
> Otherwise, the symlink expansion may not be completely done, and
> {{{$SAGE_ROOT}}} could end up with a non-canonical dirname, which leads
> to issues with testing.
>
> Here's a way to reproduce an issue with the current script. For the
> example, my sage-3.4 installation lives in {{{/home/sage/sage-3.4}}}, and
> here's what happened to me:
> {{{
> /home/sage$ md5sum sage-3.4/sage
> 4153919efe1edcd34ad7fa193122d679 sage-3.4/sage
> /home/sage$ ln -s sage-3.4 sage-3.4-symlink
> /home/sage$ ln -sf /home/sage/sage-3.4-symlink/sage
> /home/tornaria/bin/sage
> /home/sage$ type sage
> sage is hashed (/home/tornaria/bin/sage)
> /home/sage$ readlink `type -p sage`
> /home/sage/sage-3.4-symlink/sage
> /home/sage$ readlink -f `type -p sage`
> /home/sage/sage-3.4/sage
> }}}
>
> As you can see, {{{readlink -n}}} expands once but doesn't cannonicalize
> the path to the {{{sage}}} script. And here's the symptom:
> {{{
> /home/sage$ sage -t sage-3.4/devel/sage-main/sage/all.py
> sage -t "sage-3.4/devel/sage-main/sage/all.py"
> File "./all.py", line 18
> from sage-3.4/devel/sage-main/sage/all import *
> ^
> SyntaxError: invalid syntax
>
> [0.3 s]
> exit code: 1024
>
> ----------------------------------------------------------------------
> The following tests failed:
>
> sage -t "sage-3.4/devel/sage-main/sage/all.py"
> Total time for all tests: 0.3 seconds
> }}}
>
> Note that we should do this in a portable way, without using `realpath`,
> `readlink -f` or the likes. See either #6146 or #11707 for a script
> which could be used for this.
New description:
Currently, {{{$SAGE_ROOT/sage}}} uses (first among other alternate
methods) {{{readlink -n}}} to detect the directory where the script lives
(that's $SAGE_ROOT), but that is broken because
- It only works when `$0` (the sage executable itself) is a symbolic link
- If the sage executable is a symbolic link, then `readlink -n` returns
the link itself, not the canonicalized name. Example: if
`/usr/local/sage-4.7.1/sage` is a symbolic link to `sagefoo`, then
`SAGE_ROOT` would become `sagefoo` when `'/usr/local/sage-4.7.1/sagefoo`
is intended.
- The symlink expansion may not be completely done, and {{{$SAGE_ROOT}}}
could end up with a non-canonical dirname, which leads to issues with
testing.
Here's a way to reproduce an issue with the current script. For the
example, my sage-3.4 installation lives in {{{/home/sage/sage-3.4}}}, and
here's what happened to me:
{{{
/home/sage$ md5sum sage-3.4/sage
4153919efe1edcd34ad7fa193122d679 sage-3.4/sage
/home/sage$ ln -s sage-3.4 sage-3.4-symlink
/home/sage$ ln -sf /home/sage/sage-3.4-symlink/sage
/home/tornaria/bin/sage
/home/sage$ type sage
sage is hashed (/home/tornaria/bin/sage)
/home/sage$ readlink `type -p sage`
/home/sage/sage-3.4-symlink/sage
/home/sage$ readlink -f `type -p sage`
/home/sage/sage-3.4/sage
}}}
As you can see, {{{readlink -n}}} expands once but doesn't cannonicalize
the path to the {{{sage}}} script. And here's the symptom:
{{{
/home/sage$ sage -t sage-3.4/devel/sage-main/sage/all.py
sage -t "sage-3.4/devel/sage-main/sage/all.py"
File "./all.py", line 18
from sage-3.4/devel/sage-main/sage/all import *
^
SyntaxError: invalid syntax
[0.3 s]
exit code: 1024
----------------------------------------------------------------------
The following tests failed:
sage -t "sage-3.4/devel/sage-main/sage/all.py"
Total time for all tests: 0.3 seconds
}}}
Note that we should do this in a portable way, without using `realpath`,
`readlink -f` or the likes. See attachments for two bash scripts to solve
this problem (either of them should suffice).
--
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/5852#comment:17>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
