Please note that through a change to the error handling of CURL in our build.sh script, this errors appears lately with the output as seen below:

[!] /bin/bash -c
set -e
sh build.sh cocoapods-setup

core is not a symlink. Deleting...
Downloading dependency: core 0.96.1
Downloading core failed:
curl: (56) SSLRead() return error -9806

Whenever the first download via CocoaPods has failed, the cache could be in a corrupt state. It might help in such cases to remove Realm from the CocoaPods cache, what can be achieved by running the following command:

rm -rf ~/Library/Caches/CocoaPods/Pods/**/Realm*

In addition, the integration in the project should be reset.

rm -rf /Pods

After that and ensuring that you've a working internet connection without restrictions, you can run the following:

pod install --verbose

I am in china and has the same problem when I use VPN. The core realm package is 63MB, that is so big and the VPN is hard to download it. By looking the build.sh of realm, it use getconf DARWIN_USER_TEMP_DIR1 to get the tmp direction and check the $TMPDIR, if it has the core-${REALM_CORE_VERSION}.tar.bz2. So I download the https://static.realm.io/downloads/core/realm-core-0.97.1.tar.bz2 by VPN and move it to $TMPDIR, then you can pod install.

1.cd `getconf DARWIN_USER_TEMP_DIR`
2.curl https://static.realm.io/downloads/core/realm-core-0.97.1.tar.bz2 -o realm-core-0.97.1.tar.bz2
(use VPN or use the website to help download on onedrive: http://ctrlq.org/save/)
3.cd ~/yourProjectDir/
4.pod install --verbose

@madawei2699 says the correct answer. I am also a developer in China.The solution is download realm-core-XXX.tar.bz2 and copy it into /tmp/ dir. So I suggested the maintainer to list the download url of each realm version.

Wish you fix this issue ASAP. Too many developer in China work without VPN.

@Onetaway You can find the download url in
https://github.com/realm/realm-cocoa/blob/master/build.sh#L289
which is the value of CORE_URL

It's stop when "Downloading dependency: core 0.100.4".I tried these methods that mentioned above.

After Realm 2.0.x you'd want to download realm-sync-cocoa-${REALM_SYNC_VERSION}.tar.xz from https://static.realm.io/downloads/sync/realm-sync-cocoa-${REALM_SYNC_VERSION}.tar.xz into ${TMPDIR}/sync_bin, where REALM_SYNC_VERSION can be found at https://github.com/realm/realm-cocoa/blob/master/dependencies.list#L3 (currently 1.0.0-BETA-3.3), and TMPDIR should hopefully already be set in your shell environment (use getconf DARWIN_USER_TEMP_DIR if it's not).

This is ridiculous, if the developers from China needs to download the zipped file to local temp directory to let cocoapods to detect it, why not just download the dylib/static framework and add the dependency to project manually directly?

All the pods just pass except the realm-cocoa for command pod install, cocoapods brings the conveniences for developers to manage the 3rd-party packages and easy integration way. If the realm team won't support it, the China developer should switch to manual way w/o any hesitation to use it.

BTW, that would be so nice to write a note/tips in README.md file in github and realm.io/docs, since this issue has blocked so many developers. @realm-admin

BTW, I'm a developer from China. Many thanks for your great job!

I have the same problem even I use VPN and I solved it by downloading the dependence manually. In conclusion, you should download realm-core-XXX.tar.xz and realm-sync-cocoa-${REALM_SYNC_VERSION}.tar.xz, then put them into $TMPDIR/core/ and $TMPDIR/sync respectively.

I am not in China, and I am having lots of trouble installing realm. Here is the relevant bit from the "pod install verbose" output:
-> Installing Realm (2.1.1)

Git download
Git download
$ /usr/local/bin/git clone https://github.com/realm/realm-cocoa.git /var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0
--template= --single-branch --depth 1 --branch v2.1.1
Cloning into '/var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0'...
Note: checking out 'a6f8e282bdf9d44de635e44b3f8967addbdfd2c9'.

 You are in 'detached HEAD' state. You can look around, make experimental
 changes and commit them, and you can discard any commits you make in this
 state without impacting any branches by performing another checkout.
 
 If you want to create a new branch to retain commits you create, you may
 do so (now or later) by using -b with the checkout command again. Example:
 
   git checkout -b <new-branch-name>
 
 Checking out files: 100% (1101/1101), done.
 $ /usr/local/bin/git -C /var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0 submodule update --init --recursive
 Submodule 'Realm/ObjectStore' (https://github.com/realm/realm-object-store.git) registered for path 'Realm/ObjectStore'
 Cloning into '/private/var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0/Realm/ObjectStore'...
 Submodule path 'Realm/ObjectStore': checked out 'bedfafd264ffe823a633cac582036ca31be69793'
 Submodule 'external/catch' (https://github.com/philsquared/Catch) registered for path 'Realm/ObjectStore/external/catch'
 Submodule 'external/pegtl' (https://github.com/ColinH/PEGTL) registered for path 'Realm/ObjectStore/external/pegtl'
 Cloning into '/private/var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0/Realm/ObjectStore/external/catch'...
 Cloning into '/private/var/folders/w4/x6y651ks4zq9jx00gbth2wd5hlmvrr/T/d20161219-5097-12umqi0/Realm/ObjectStore/external/pegtl'...
 Submodule path 'Realm/ObjectStore/external/catch': checked out 'f294c9847272b1b92c5119a6f711e57113b5f231'
 Submodule path 'Realm/ObjectStore/external/pegtl': checked out '3c4128a7e7e1288eb746418ea60c41477358f26a'

Running prepare command
$ /bin/bash -c set -e sh build.sh cocoapods-setup
[!] /bin/bash -c
set -e
sh build.sh cocoapods-setup

wtf is going on??

@danat8x8 what's wrong with the installation? The log output you shared doesn't seem to indicate a failure of any kind...

If by your own admission your issue is unrelated to what this issue is tracking, why not open a new issue, taking care to fill out the new issue template, and include the full output of pod install --verbose? Thanks!

apologies, I was typing before thinking. there is an error when it tries to install Realm, that I can't resolve. I'll open another issue.

I am in china and has the same problem when I use VPN..Place tell me how to host success

     Submodule path 'Realm/ObjectStore/external/catch': checked out 'ce37f48ffad2401e6c23a54cae3f015c01fdc200'
     Submodule path 'Realm/ObjectStore/external/pegtl': checked out '3c4128a7e7e1288eb746418ea60c41477358f26a'
 > Running prepare command
   $ /bin/bash -c  set -e sh build.sh cocoapods-setup
   core is not a symlink. Deleting...
   Downloading dependency: sync 1.10.0

[!] /bin/bash -c 
set -e
sh build.sh cocoapods-setup

core is not a symlink. Deleting...
Downloading dependency: sync 1.10.0
Downloading sync failed:
	https://static.realm.io/downloads/sync/realm-sync-cocoa-1.10.0.tar.xz
	curl: (28) Operation timed out after 300294 milliseconds with 0 out of 0 bytes received

I am facing this problem today, the @madawei2699 is right.
In addition:
for RealmSiwft 2.10.0 source path:
https://static.realm.io/downloads/sync/realm-sync-cocoa-1.10.8.tar.xz
and then pull the file into /tmp/dir, pod install again is OK.

The speed almost drives me mad, I don't understand my previous colleague choose this database, but he already leave the company, just because this database can cause a lot of trouble?

@kimown
you should download the blew two files:

cocoa:
https://static.realm.io/downloads/sync/realm-sync-cocoa-1.10.8.tar.xz

core:
https://static.realm.io/downloads/core/realm-core-2.8.1.tar.xz

and put them into $TMPDIR/sync & $TMPDIR/core/ separately. So, it can save your a lot of time.

It's only necessary to download the former file. The latter is not used.

Realm is the best DB library i found for iOS. I love, but i live in Cuba, and cloudflare (realm.io) is making me going crazy every time i need install them. Using Speedify (a really good and speedy VPN) i will take 2 or 3 ours to achieve this task. Please do something, move the core to a domain that don´t block countries. Realm is the unique library in the world giving problems when installed with CocoaPods. Help please !

And please can u edit install.sh and tell curl to display network info when downloading core?, for example:

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
88 117M 88 104M 0 0 168k 0 0:11:58 0:10:34 0:01:24 0

@wonder2011 have you considered migrating to SPM, which will only download code from GitHub and will not require to download core's monorepo from "https://static.realm.io/downloads"