While attempting to install python via pyenv, I was hitting the a frustrating dynamic link error for openssl, even though I'd installed and configured openssl@1.1 via homebrew months prior:
$ pyenv install -v 3.8.2
pyenv: /Users/fire/.pyenv/versions/3.8.2 already exists
continue with installation? (y/N) y
python-build: use openssl@1.1 from homebrew
python-build: use readline from homebrew
/var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807114817.54648 ~/projects
Downloading Python-3.8.2.tar.xz...
-> https://www.python.org/ftp/python/3.8.2/Python-3.8.2.tar.xz
dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib
Referenced from: /usr/local/opt/libssh2/lib/libssh2.1.dylib
Reason: image not found
/usr/local/bin/python-build: line 355: 55387 Abort trap: 6 aria2c --allow-overwrite=true --no-conf=true -o "${out}" ${ARIA2_OPTS} "$1" 1>&4
error: failed to download Python-3.8.2.tar.xz
BUILD FAILED (OS X 10.14.6 using python-build 20180424)
I'd double checked all of my paths for openssl@1.1, tried reinstalling pyenv via homebrew, etc., and nothing to this point had worked.
In short: Check the libraries referencing the missing dynamic library, and confirm you've re-built them after changing openssl versions as well.
You can rebuild either via a version upgrade with brew upgrade or a reinstallation of the problematic package via brew reinstall.
Why? Homebrew does not appear to consider libssh2 a dependent of openssl@1.1, and thus does not rebuild it automatically as it otherwise would.
Investigatory debug process:
After wracking my brain, google, and SO for an hour, I took yet another look at the failure:
dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib
Referenced from: /usr/local/opt/libssh2/lib/libssh2.1.dylib
Reason: image not found
From there, I noticed that libssh2 was the cause of the failed reference:
Referenced from: /usr/local/opt/libssh2/lib/libssh2.1.dylib
On a whim, I checked the version of libssh2 homebrew had installed:
$ brew info libssh2
libssh2: stable 1.9.0 (bottled), HEAD
C library implementing the SSH2 protocol
https://libssh2.org/
/usr/local/Cellar/libssh2/1.8.0 (182 files, 798.7KB) *
Poured from bottle on 2018-11-14 at 17:45:34
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/libssh2.rb
License: BSD-3-Clause
==> Dependencies
Required: openssl@1.1 ā
==> Options
--HEAD
Install HEAD version
==> Analytics
install: 38,765 (30 days), 110,674 (90 days), 607,725 (365 days)
install-on-request: 2,946 (30 days), 4,789 (90 days), 19,954 (365 days)
build-error: 0 (30 days)
Ah, that might be it! This was installed back in 2018!
Poured from bottle on 2018-11-14 at 17:45:34
One brew upgrade libssh2 later and we're in business
==> Upgrading 1 outdated package:
libssh2 1.8.0 -> 1.9.0_1
==> Upgrading libssh2 1.8.0 -> 1.9.0_1
==> Downloading https://homebrew.bintray.com/bottles/libssh2-1.9.0_1.mojave.bottle.tar.gz
==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/327c56ad6a54894e5ef9aa3019d2444d32f1d0fba80925940100e517dd3109c9?response-content-disposition=attachment%3Bfilename%3D%22libssh2-1.9.0_1.mojave.bottle.tar.gz%22&Policy
######################################################################## 100.0%
==> Pouring libssh2-1.9.0_1.mojave.bottle.tar.gz
šŗ /usr/local/Cellar/libssh2/1.9.0_1: 184 files, 942KB
Removing: /usr/local/Cellar/libssh2/1.8.0... (182 files, 798.7KB)
...
And from there, our initial problem is resolved:
$ pyenv install -v 3.8.2
pyenv: /Users/fire/.pyenv/versions/3.8.2 already exists
continue with installation? (y/N) y
python-build: use openssl@1.1 from homebrew
python-build: use readline from homebrew
/var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807115352.60918 ~/projects
Downloading Python-3.8.2.tar.xz...
-> https://www.python.org/ftp/python/3.8.2/Python-3.8.2.tar.xz
08/07 11:53:54 [NOTICE] Downloading 1 item(s)
[#25162c 0B/0B CN:1 DL:0B]
08/07 11:53:55 [NOTICE] Allocating disk space. Use --file-allocation=none to disable it. See --file-allocation option in man page for more details.
[#25162c 9.0MiB/17MiB(52%) CN:1 DL:9.8MiB]
08/07 11:53:56 [NOTICE] Download complete: /private/var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807115352.60918/Python-3.8.2.tar.xz
Download Results:
gid |stat|avg speed |path/URI
======+====+===========+=======================================================
25162c|OK | 9.9MiB/s|/private/var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807115352.60918/Python-3.8.2.tar.xz
Status Legend:
(OK):download completed.
/var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807115352.60918/Python-3.8.2 /var/folders/c3/cmbbfq710rvdh4l82q2h_86ds4cblh/T/python-build.20200807115352.60918 ~/projects
Installing Python-3.8.2...
python-build: use readline from homebrew
python-build: use zlib from xcode sdk
checking build system type... x86_64-apple-darwin18.7.0
...