Fix "sage -info" and a bug when sourcing sage-env more than once

[jhpalmieri]

One of the patches at #9960 did a lot of clean-up to the file sage-spkg: quoting environment variables, replacing tabs with spaces, etc., also adding comments and TODOs. Since those changes were not related to the issue at #9960, I've split them off and put them here instead. The main change of any content is to look at the file SPKG.txt rather than SAGE.txt when the "-info" flag is passed so sage-spkg (through sage -info ...). Also, warnings and error messages are now redirected to stderr.

The additional patch to sage-spkg is based on the v2 "clean-up" patch, fixing some more bugs, adding error checks, improving some messages (see comment below / commit message for some more details).

Apparently support for sage -info ... was removed at some point (or never existed); the patch to sage-sage fixes that.

The patch to sage-env fixes a bug caused or enabled by #10469, which through the patch to sage-spkg now becomes more visible and potentially worse.

Apply

1. trac_11021-sage-spkg-cleanup-v2-rebased_to_4.7.1.alpha4.patch​
2. trac_11021-additional_changes_to_sage-spkg.scripts.patch​ (somewhat optional, can be reviewed separately)
3. trac_11021-support_and_document_sage_-info_in_sage-sage.scripts.patch​
4. trac_11021-export_BUILD_in_sage-env.scripts.patch​

to the scripts repo.

[ltw]

Patch has been rebased to sage 4.7. However, there is a problem on lines 136-143 in sage-spkg (after patch has been applied). The return code check doesn't do anything after the statement echo "", because that overwrites $? to 0. I can't figure out the intent of the preceding tar command, so I don't know how to fix this problem. Could someone help me?

[leif]

Well, the code is a bit weird anyway; there should be an exit 1 if the package ($PKG_SRC) does not exist:

if [ "$INFO" -ne 0 ]; then
    if [ ! -f "$PKG_SRC" ]; then
        echo "Package $PKG_NAME not found"
        # EXIT HERE
    fi
    ...

I don't think we really need the echo "", since SPKG.txt files should be newline-terminated. (The tar commands extract this file to stdout.)

---

As far as I know, there are indeed (at least some old, optional) packages that do have a short SAGE.txt (rather than SPKG.txt), so I'm not sure if we shouldn't check for both.

Also, typical SPKG.txt files are quite long, so we might omit some parts or e.g. "cut" them where the Changelog section starts.

[ltw]

Leif, I have updated the patch according to your first two suggestions. I don't know what to do with SAGE.txt or truncating long SPKG.txt files. I'm thinking that we should put those "real" changes in another ticket (or does one already exist?).

[leif]

Replying to ltw:

Leif, I have updated the patch according to your first two suggestions.

Ok, though I wouldn't have changed the "error" message; the previous one sounds a bit friendlier. (Actually a non-zero status code can have a couple of reasons there, but I don't mind. ;-) )

I don't know what to do with SAGE.txt or truncating long SPKG.txt files. I'm thinking that we should put those "real" changes in another ticket (or does one already exist?).

Maybe John has some idea or opinion on that...

(We could e.g. pipe the tar output to some sort of sed -e '/== Changelog ==/,$d' and perhaps give some message indicating it was omitted. Not important to me; maybe users less familiar with more or less could enjoy that - I personally don't use the -info option at all.)

[ltw]

Replying to leif:

Ok, though I wouldn't have changed the "error" message; the previous one sounds a bit friendlier. (Actually a non-zero status code can have a couple of reasons there, but I don't mind. ;-) )

A few lines above, there is an error message "Package $PKG_NAME not found". So I thought "File SPKG.txt not found in package $PKG_NAME" would follow the same grammar. But I can change it back, no problem. :-)

(We could e.g. pipe the tar output to some sort of sed -e '/== Changelog ==/,$d' and perhaps give some message indicating it was omitted.

That's pretty hackish in my opinion. It would impose an undocumented constraint on the format of SPKG.txt, which does not have any formatting validation otherwise. I'm not sure that truncating SPKG.txt is even desirable.

[leif]

Replying to ltw:

Replying to leif:

Ok, though I wouldn't have changed the "error" message; the previous one sounds a bit friendlier. (Actually a non-zero status code can have a couple of reasons there, but I don't mind. ;-) )

A few lines above, there is an error message "Package $PKG_NAME not found". So I thought "File SPKG.txt not found in package $PKG_NAME" would follow the same grammar. But I can change it back, no problem. :-)

What about "Could not extract SPKG.txt." or better "Package $PKG_NAME appears to have no SPKG.txt."?

Redirecting stderr of the tar commands to /dev/null is a bit odd there. On the other hand, the presence of $PKG_SRC (the spkg file) itself is checked twice a few lines above, so a non-zero exit code of tar most probably means either a corrupted tarball or the file to extract wasn't found. Maybe the proper way would be to first try to list the file (tar tf - ... 2>/dev/null) into some shell variable and check if it is empty (or, better, list the tarball's whole contents grepping for $PKG_NAME/SPKG.txt), and use bunzip2 -t ... to test whether the spkg is compressed in advance.

Or verify the spkg wasn't corrupted in case of an error ($? -ne 0):

    ...
    if [ $? -ne 0 ]; then
        # Extracting SPKG.txt failed for *some* reason,
        # now check if it's simply missing:
        if (bunzip2 -c "$PKG_SRC" | tar tf -) &>/dev/null ||
           tar tf "$PKG_SRC" &>/dev/null
        then
            echo "Package $PKG_NAME lacks a description (SPKG.txt file)."
            exit 1
        else
            echo "$PKG_SRC seems to be corrupted. Exiting."
            exit 1 # or some other error code
        fi
    fi
    exit 0
fi

But IMHO a rather minor issue.

(We could e.g. pipe the tar output to some sort of sed -e '/== Changelog ==/,$d' and perhaps give some message indicating it was omitted.

That's pretty hackish in my opinion. It would impose an undocumented constraint on the format of SPKG.txt, which does not have any formatting validation otherwise. I'm not sure that truncating SPKG.txt is even desirable.

SPKG.txt files are supposed to have a quite clear structure, with ReST (section) mark-up (which an spkg reviewer should check btw). If there's no line matching == Changelog == -- or preferably a more generic, i.e. robust pattern, nothing would get omitted.

But as I said, I have no opinion on truncating them there.

[leif]

P.S.: I wonder if we shouldn't also redirect all warning and error messages to stderr (echo >2 "..."). We just recently started doing so in a couple of other scripts, so it's not yet consistent within Sage, but an ongoing change.

[leif]

Replying to leif:

I wonder if we shouldn't also redirect all warning and error messages to stderr (echo >2 "...").

echo >&2 "..." of course.

[ltw]

Replying to leif:

What about "Could not extract SPKG.txt." or better "Package $PKG_NAME appears to have no SPKG.txt."?

I have decided to follow the original phrasing: "No file SPKG.txt in package $PKG_NAME".

Or verify the spkg wasn't corrupted in case of an error ($? -ne 0):

<SNIP>

But IMHO a rather minor issue.

I didn't touch it for this patch update; I'll have to think about it later. :-)

SPKG.txt files are supposed to have a quite clear structure, with ReST (section) mark-up (which an spkg reviewer should check btw). If there's no line matching == Changelog == -- or preferably a more generic, i.e. robust pattern, nothing would get omitted.

But as I said, I have no opinion on truncating them there.

Also didn't change anything here. I didn't know that SPKG.txt is supposed to be structured; honestly I've never even read one. O_o

Replying to leif:

P.S.: I wonder if we shouldn't also redirect all warning and error messages to stderr (echo >2 "..."). We just recently started doing so in a couple of other scripts, so it's not yet consistent within Sage, but an ongoing change.

I have changed a number of these. I wasn't sure on a few cases; please check them.

I also replaced a few instances of echo "*************" with a common function call (print_separator). I'm not sure whether this was a good idea. Please criticize!

[leif]

Hmmm, for Sage 4.7.1.alpha4, we'll have to rebase the patch:

applying /home/leif/Sage/patches/trac_11021-sage-spkg-cleanup-v2.patch
patching file sage-spkg
Hunk #3 succeeded at 59 (offset 4 lines).
Hunk #4 succeeded at 93 (offset 4 lines).
Hunk #5 succeeded at 139 (offset 4 lines).
Hunk #6 succeeded at 164 (offset 4 lines).
Hunk #7 succeeded at 183 (offset 4 lines).
Hunk #8 succeeded at 191 (offset 4 lines).
Hunk #9 succeeded at 226 (offset 4 lines).
Hunk #10 succeeded at 250 (offset 4 lines).
Hunk #11 succeeded at 273 (offset 4 lines).
Hunk #12 succeeded at 292 (offset 4 lines).
Hunk #13 FAILED at 304
Hunk #14 succeeded at 402 (offset 4 lines).
Hunk #15 succeeded at 413 (offset 4 lines).
Hunk #16 succeeded at 439 (offset 4 lines).
1 out of 16 hunks FAILED -- saving rejects to file sage-spkg.rej
abort: patch failed to apply

Sorry for the delay btw, been busy with other things.

Though there are still some things that could be improved (e.g. still two instances of build rather than $BUILD IIRC), and I would have put the >&2 right after echo to be more obvious, I'm ok with your changes.

I.e., I'll rebase the patch as is, test it, and if you're ok with my previous changes, we'd have a positive review.

(Other things like supporting SAGE_CHECK=ignore and what else we've mentioned on this ticket can be implemented on follow-ups, we just have to get this ticket merged first... :) )

[leif]

SCRIPTS repo. Version 2 simply rebased to Sage 4.7.1.alpha4.

[leif]

Replying to leif:

I'll rebase the patch as is.

Done.

[leif]

SCRIPTS repo. Fix BUILD not being set if sage-env is sourced a second time. Based on Sage 4.7.1.alpha4.

[leif]

SCRIPTS repo. Implements/supports & documents "sage -info ..." in sage-sage; minor fixes. Based on Sage 4.7.1.alpha4.

[leif]

The other two patches I've attached fix issues that came up while testing the patch to sage-spkg with Sage 4.7.1.alpha4.

They're both necessary to make sage -info ... as well as sage-spkg in general (with the changes made by the other patch) work.

Cf. ​http://trac.sagemath.org/sage_trac/ticket/10469#comment:24.

Please review!

[leif]

I've made some more changes to sage-spkg (more than I intended):

• Fixed some bugs, e.g. not recording the version of a package found in spkg/{standard,optional} such that the installation later failed; superfluous second download now doesn't take place.
• All instances of build now use $BUILD. (It is now also checked that BUILD is really set, cf. patch to sage-env.)
• More error checks and more appropriate error messages.
• Non-conforming spkgs are no longer said to be corrupted.
• Default installation scripts now use $MAKE rather than make ($MAKE -j1 for installation).
• spkg-check is now timed, too.
• Trying to install an already installed spkg now suggests using -f.
• Some restructuring and simplification, removed useless code.
• Lots of comments (including TODOs) added, some cosmetic changes.

Harder to review, but please also do. ;-)

(Patch is based on the rebased v2, i.e. should be applied after that.)

[leif]

SCRIPTS repo. Bug fixes, more error checks, improved messages, restructuring. Apply on top of the rebased v2-patch.

[leif]

New patch is up now.