If the underneath file system is a Network File System,
`brew cleanup` will fail to remove the lock files with following error
message:
Error: Bad file descriptor @ rb_file_flock - /path/to/the/lock_file
This commit fixes such issue and adds the corresponding test case.
Sometimes, `brew cask fetch`/`install` fails with an error message
similar to this:
```
==> Downloading https://w3g3a5v6.ssl.hwcdn.net/upload2/game/214692/735
Error: Download failed on Cask 'steamed-hams' with message: Operation
not supported @ rb_sysopen -
/Users/claudia/Documents/dev/brew/var/homebrew/locks/steamed-hams--1.0
.com&Expires=1520937180&Signature=CGmDulxL8pmutKTlCleNTUY%2FyO9Xyl5u9y
VZUE0uWrjadjuz67Jp7zx3H7NEOhSyOhu8nzicEHRBjr3uSoOJzwkLC8LBLKnz%2B2X%2B
iq5m6IdwSVFcLp2Q1Hr2kR7ETn3rF1DIq5o0lHCyzMmyNe5giEKJNW8WF0KXriULhzLTWL
SA3ZTLCIofAdRiiGje1kNYY3C0SBqymQB8CG3ONn5kj7CIGbxrDOq5xI2ZSJdIyPysSX7S
LvEDBw2KdR24q9t1wfjS9LUzelf5TWk6ojj8p9%2FHjl%2Fi%2FVCXNN4o1mW%2FMayy2t
TY1qcC%2FTmqI1ulZS8SNuaSgr9Iys9oDF1%2BPK%2B4Sg==&hwexp=1520937440&hwsi
g=55bc66884b925ef22f8673c33bfcc33b.incomplete.lock
```
To reproduce the issue, check out this branch and run the
`cask/download_strategy` test suite:
```
brew tests --only=cask/download_strategy
```
Or take a real-life example, which would be a Cask whose URL has
**1.** no `.` character anywhere in the URL path itself (outside of
the domain name), **and 2.** at least one query parameter with a `.`
character in it; **and 3.** other query parameters following that
with a combined length of more than 255 characters.
This combination may be uncommon but it exists, especially in
[URLs that change on every visit](1002d41242/doc/cask_language_reference/stanzas/url.md (urls-that-change-on-every-visit)),
for example
[`steamed-hams`](9d7df499cd/Casks/steamed-hams.rb)
from my `claui/cask-games` tap:
$ brew tap claui/cask-games
$ brew cask fetch steamed-hams
In a nutshell, **URL query strings sometimes look like a very long
file extension to Homebrew,** which it then proceeds to use as a file
name.
In `CurlDownloadStrategy`, Homebrew seems to apply a heuristic to the
cask URL in order to figure out a possibly meaningful file extension.
Sometimes this heuristic produces immensely long file extensions,
especially when there’s a query parameter with a `.` character in it
but not in the URL path itself (outside of the domain name).
Homebrew then believes that everything after the `.` is a file
extension. In one of the later steps, it tries to create a lock file
containing that extension, which fails because HFS+ cannot handle
files whose base file name has more than 255 characters.
One solution would be to improve Homebrew’s extension detector a bit
so that it won’t cross individual URL query param boundaries any
longer. This is done by adding `&` as a stop character:
```
def ext
Pathname.new(@url).extname[/[^?&]+/]
end
```
This appears to fix the issue for most (if not all) practical
purposes.
These instructions are currently incorrect and need to be ported to
`python` 3.x and `python@2` formulae. Until then it's better to not have
them than have them be incorrect.
Closes#3890.
Remove more Requirement logic to enable future removal of default
formula logic. Also, output deprecations, convert symbol requirement
usage to deps and simplify the compatibility code for the direct
Requirement usage.
