Bug 240634

Summary:	lang/rust: Rust build uses Python 2.7 on system that has Python 3.6 as default Python version
Product:	Ports & Packages	Reporter:	Vincent Bentley <vince>
Component:	Individual Port(s)	Assignee:	FreeBSD Rust Team <rust>
Status:	Closed FIXED
Severity:	Affects Only Me	CC:	koobs, python, rust
Priority:	---	Flags:	tobik: maintainer-feedback+
Version:	Latest
Hardware:	Any
OS:	Any
See Also:	https://github.com/rust-lang/rust/issues/59838

Description Vincent Bentley 2019-09-17 10:23:09 UTC

The maintenance period of Python 2.7 ends on 1 January 2020.

I noticed that building Rust under Poudriere on FreeBSD 12.0p10 uses Python 2.7 even when the build host has been configured to default to Python 3.6 .

Using Python 2.7 does not prevent building Rust successfully in 2019 but it may become an issue in three and a half months time.

Excerpts from Poudriere build log for Rust...

--CONFIGURE_ENV--
MAKE=gmake PKG_CONFIG=pkgconf PYTHON="/usr/local/bin/python2.7" XDG_DATA_HOME=/wrkdirs/usr/ports/lang/rust/work  XDG_CONFIG_HOME=/wrkdirs/usr/ports/lang/rust/work  HOME=/wrkdirs/usr/ports/lang/rust/work TMPDIR="/tmp" PATH=/wrkdirs/usr/ports/lang/rust/work/.bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/root/bin SHELL=/bin/sh CONFIG_SHELL=/bin/sh CMAKE_PREFIX_PATH="/usr/local"
--End CONFIGURE_ENV--

...

--PLIST_SUB--
RUST_TARGET=x86_64-unknown-freebsd PORTDOCS="" PYTHON_INCLUDEDIR=include/python2.7  PYTHON_LIBDIR=lib/python2.7  PYTHON_PLATFORM=freebsd12  PYTHON_SITELIBDIR=lib/python2.7/site-packages  PYTHON_SUFFIX=27  PYTHON_VER=2.7  PYTHON_VERSION=python2.7 PYTHON2="" PYTHON3="@comment " OSREL=12.0 PREFIX=%D LOCALBASE=/usr/local  RESETPREFIX=/usr/local LIB32DIR=lib DOCSDIR="share/doc/rust"  EXAMPLESDIR="share/examples/rust"  DATADIR="share/rust"  WWWDIR="www/rust"  ETCDIR="etc/rust"
--End PLIST_SUB--

...

===>   Returning to build of rust-1.37.0
===>   rust-1.37.0 depends on file: /usr/local/bin/python2.7 - not found
===>   Installing existing package /packages/All/python27-2.7.16_1.txz
[s205] Installing python27-2.7.16_1...
[s205] `-- Installing libffi-3.2.1_3...
[s205] `-- Extracting libffi-3.2.1_3: .......... done
[s205] Extracting python27-2.7.16_1: .......... done

...

=======================<phase: build          >============================
===>  Building for rust-1.37.0
cd /wrkdirs/usr/ports/lang/rust/work/rustc-1.37.0-src &&  /usr/bin/env HOME="/wrkdirs/usr/ports/lang/rust/work"  LIBGIT2_SYS_USE_PKG_CONFIG=1  LIBSSH2_SYS_USE_PKG_CONFIG=1  OPENSSL_DIR="/usr"  /usr/local/bin/python2.7 /wrkdirs/usr/ports/lang/rust/work/rustc-1.37.0-src/x.py build  --verbose  --config ./config.toml  --jobs 4

Comment 1 Kubilay Kocak freebsd_committer

2019-09-17 10:41:40 UTC

Thank you for the report Vincent

For context DEFAULT_VERSIONS are *just* defaults, there is nothing precluding particular ports from specifying versions of Python that they support, that don't match the defaults.

In rusts case, the port currently specifies "python:2.7", which should either mean "only supports 2.7" or in case a particular version is currently (temporarily) broken, "only use 2.7". In either case at present, its 'correct and intentional behaviour' for the port to use Python 2.7.

If however, rust otherwise supports other Python versions and the port has not correctly or completely declared Python version support (in its USES=python:<version-spec>), or is unnecessarily restricting <version-spec>, that's a bug.

Comment 2 Tobias Kortkamp freebsd_committer

2019-09-27 09:40:49 UTC

Switched to USES=python:build in ports r513013.